ETH Price: $2,541.28 (+1.02%)

Transaction Decoder

Block:
20906715 at Oct-06-2024 01:09:47 PM +UTC
Transaction Fee:
0.00121369395998871 ETH $3.08
Gas Used:
172,215 Gas / 7.047550794 Gwei

Emitted Events:

337 BNB.Transfer( from=[Sender] 0xf6b95b2461a4044f00fe274baa07d90ad091f1c4, to=ERC20Router, value=29253412329061369 )
338 WETH9.Transfer( src=0x9E7809C21BA130c1A51C112928eA6474D9a9Ae3C, dst=ZeroEx, wad=6709545968661950 )
339 BNB.Transfer( from=ERC20Router, to=0x9E7809C21BA130c1A51C112928eA6474D9a9Ae3C, value=29253412329061369 )
340 0x9e7809c21ba130c1a51c112928ea6474d9a9ae3c.0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67( 0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67, 0x000000000000000000000000def1c0ded9bec7f1a1670819833240f027b25eff, 0x000000000000000000000000def1c0ded9bec7f1a1670819833240f027b25eff, 0000000000000000000000000000000000000000000000000067edd2d2577bf9, ffffffffffffffffffffffffffffffffffffffffffffffffffe829b417ef0a42, 00000000000000000000000000000000000000007b3832786ca0806e5cb0a6c3, 00000000000000000000000000000000000000000000008e1339e062df032456, ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffc6df )
341 WETH9.Withdrawal( src=ZeroEx, wad=6709545968661950 )

Account State Difference:

  Address   Before After State Difference Code
(beaverbuild)
12.755134440994847301 Eth12.755143051744847301 Eth0.00000861075
0x9E7809C2...4D9a9Ae3C
(Uniswap V3: BNB 2)
0xB8c77482...C631bDD52
0xC02aaA39...83C756Cc2 2,969,238.671461856049333032 Eth2,969,238.664752310080671082 Eth0.00670954596866195
0xf6B95B24...ad091F1C4
0.002743914561556917 Eth
Nonce: 11
0.001530220601568207 Eth
Nonce: 12
0.00121369395998871
0xf70da978...8dfA3dbEF 333.574061309428536842 Eth333.580770855397198792 Eth0.00670954596866195

Execution Trace

ApprovalProxy.transferAndMulticall( tokens=[0xB8c77482e45F1F44dE1745F52C74426C631bDD52], amounts=[29253412329061369], targets=[0xB8c77482e45F1F44dE1745F52C74426C631bDD52, 0xDef1C0ded9bec7F1a1670819833240f027b25EfF], datas=[CV6nswAAAAAAAAAAAAAAAN7xwN7ZvsfxoWcIGYMyQPAnsl7/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGft0tJXe/k=, gDuibQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGft0tJXe/kAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAF5lGBwaMyQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACu4x3SC5F8fRN4XRfUsdEJsYxvdUgAnEMAqqjmyI/6NCg5cTyfq2Qg8dWzCAAAAAAAAAAAAAAAAAAAAAAAAAAAAhpWEzQAAAAAAAAAAAAAAAJTTJaazGue7ePQ/uX2kN8HD9C+WAAAAAAAAAAAAAAAAAAAAAAAAAADIRtbkzTWzWQGFSxI=], values=[0, 0], refundTo=0xf70da97812CB96acDF810712Aa562db8dfA3dbEF ) => ( 0x00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000017D64BE810F5BE )
  • BNB.transferFrom( _from=0xf6B95B2461a4044f00FE274BAA07d90ad091F1C4, _to=0xA1BEa5fe917450041748Dbbbe7E9AC57A4bBEBaB, _value=29253412329061369 ) => ( success=True )
  • ERC20Router.delegatecallMulticall( targets=[0xB8c77482e45F1F44dE1745F52C74426C631bDD52, 0xDef1C0ded9bec7F1a1670819833240f027b25EfF], datas=[CV6nswAAAAAAAAAAAAAAAN7xwN7ZvsfxoWcIGYMyQPAnsl7/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGft0tJXe/k=, gDuibQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGft0tJXe/kAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAF5lGBwaMyQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACu4x3SC5F8fRN4XRfUsdEJsYxvdUgAnEMAqqjmyI/6NCg5cTyfq2Qg8dWzCAAAAAAAAAAAAAAAAAAAAAAAAAAAAhpWEzQAAAAAAAAAAAAAAAJTTJaazGue7ePQ/uX2kN8HD9C+WAAAAAAAAAAAAAAAAAAAAAAAAAADIRtbkzTWzWQGFSxI=], values=[0, 0], refundTo=0xf70da97812CB96acDF810712Aa562db8dfA3dbEF ) => ( 0x00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000017D64BE810F5BE )
    • Multicaller.aggregate( targets=[0xB8c77482e45F1F44dE1745F52C74426C631bDD52, 0xDef1C0ded9bec7F1a1670819833240f027b25EfF], data=[CV6nswAAAAAAAAAAAAAAAN7xwN7ZvsfxoWcIGYMyQPAnsl7/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGft0tJXe/k=, gDuibQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGft0tJXe/kAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAF5lGBwaMyQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACu4x3SC5F8fRN4XRfUsdEJsYxvdUgAnEMAqqjmyI/6NCg5cTyfq2Qg8dWzCAAAAAAAAAAAAAAAAAAAAAAAAAAAAhpWEzQAAAAAAAAAAAAAAAJTTJaazGue7ePQ/uX2kN8HD9C+WAAAAAAAAAAAAAAAAAAAAAAAAAADIRtbkzTWzWQGFSxI=], values=[0, 0], refundTo=0xf70da97812CB96acDF810712Aa562db8dfA3dbEF ) => ( [AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAE=, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABfWS+gQ9b4=] )
      • BNB.approve( _spender=0xDef1C0ded9bec7F1a1670819833240f027b25EfF, _value=29253412329061369 ) => ( success=True )
      • ZeroEx.803ba26d( )
        • UniswapV3Feature.sellTokenForEthToUniswapV3( encodedPath=0xB8C77482E45F1F44DE1745F52C74426C631BDD52002710C02AAA39B223FE8D0A0E5C4F27EAD9083C756CC2, sellAmount=29253412329061369, minBuyAmount=6642450508975305, recipient=0x0000000000000000000000000000000000000000 ) => ( buyAmount=6709545968661950 )
          • Uniswap V3: BNB 2.128acb08( )
            • WETH9.transfer( dst=0xDef1C0ded9bec7F1a1670819833240f027b25EfF, wad=6709545968661950 ) => ( True )
            • BNB.balanceOf( 0x9E7809C21BA130c1A51C112928eA6474D9a9Ae3C ) => ( 159941827238770601502 )
            • ZeroEx.fa461e33( )
            • BNB.balanceOf( 0x9E7809C21BA130c1A51C112928eA6474D9a9Ae3C ) => ( 159971080651099662871 )
            • WETH9.withdraw( wad=6709545968661950 )
              • ETH 0.00670954596866195 ZeroEx.CALL( )
              • ETH 0.00670954596866195 ERC20Router.CALL( )
              • ETH 0.00670954596866195 0xf70da97812cb96acdf810712aa562db8dfa3dbef.CALL( )
                transferAndMulticall[ApprovalProxy (ln:37)]
                File 1 of 7: ApprovalProxy
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.23;
                import {Ownable} from "solady/src/auth/Ownable.sol";
                import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
                import {IERC20Router} from "../src/types/interfaces/IERC20Router.sol";
                contract ApprovalProxy is Ownable {
                    using SafeERC20 for IERC20;
                    error ArrayLengthsMismatch();
                    error ERC20TransferFromFailed();
                    error NativeTransferFailed();
                    event RouterUpdated(address newRouter);
                    address public router;
                    receive() external payable {}
                    constructor(address _owner, address _router) {
                        _initializeOwner(_owner);
                        router = _router;
                    }
                    /// @notice Withdraw function in case funds get stuck in contract
                    function withdraw() external onlyOwner {
                        _send(msg.sender, address(this).balance);
                    }
                    /// @notice Set the router address
                    /// @param _router The address of the router contract
                    function setRouter(address _router) external onlyOwner {
                        router = _router;
                        emit RouterUpdated(_router);
                    }
                    /// @notice Transfer tokens to ERC20Router and perform multicall in a single tx
                    /// @dev This contract must be approved to transfer msg.sender's tokens to the ERC20Router
                    /// @param tokens An array of token addresses to transfer
                    /// @param amounts An array of token amounts to transfer
                    /// @param targets An array of target addresses to pass to the multicall
                    /// @param datas An array of calldata to pass to the multicall
                    /// @param values An array of msg values to pass to the multicall
                    /// @param refundTo The address to refund any leftover ETH to
                    function transferAndMulticall(
                        address[] calldata tokens,
                        uint256[] calldata amounts,
                        address[] calldata targets,
                        bytes[] calldata datas,
                        uint256[] calldata values,
                        address refundTo
                    ) external payable returns (bytes memory) {
                        // Revert if array lengths do not match
                        if ((tokens.length != amounts.length)) {
                            revert ArrayLengthsMismatch();
                        }
                        // Revert if array lengths do not match (split from above for readability)
                        if (targets.length != datas.length || datas.length != values.length) {
                            revert ArrayLengthsMismatch();
                        }
                        // Transfer the tokens to the router
                        for (uint256 i = 0; i < tokens.length; i++) {
                            IERC20(tokens[i]).safeTransferFrom(msg.sender, router, amounts[i]);
                        }
                        // Call delegatecallMulticall on the router. The router will perform a
                        // delegatecall to the Multicaller.
                        // @dev msg.sender for the calls to targets will be the router
                        bytes memory data = IERC20Router(router).delegatecallMulticall{value: msg.value}(
                            targets,
                            datas,
                            values,
                            refundTo
                        );
                        return data;
                    }
                    function _send(address to, uint256 value) internal {
                        bool success;
                        assembly {
                            // Save gas by avoiding copying the return data to memory.
                            // Provide at most 100k gas to the internal call, which is
                            // more than enough to cover common use-cases of logic for
                            // receiving native tokens (eg. SCW payable fallbacks).
                            success := call(100000, to, value, 0, 0, 0, 0)
                        }
                        if (!success) {
                            revert NativeTransferFailed();
                        }
                    }
                }// SPDX-License-Identifier: MIT
                pragma solidity ^0.8.4;
                /// @notice Simple single owner authorization mixin.
                /// @author Solady (https://github.com/vectorized/solady/blob/main/src/auth/Ownable.sol)
                ///
                /// @dev Note:
                /// This implementation does NOT auto-initialize the owner to `msg.sender`.
                /// You MUST call the `_initializeOwner` in the constructor / initializer.
                ///
                /// While the ownable portion follows
                /// [EIP-173](https://eips.ethereum.org/EIPS/eip-173) for compatibility,
                /// the nomenclature for the 2-step ownership handover may be unique to this codebase.
                abstract contract Ownable {
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                       CUSTOM ERRORS                        */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev The caller is not authorized to call the function.
                    error Unauthorized();
                    /// @dev The `newOwner` cannot be the zero address.
                    error NewOwnerIsZeroAddress();
                    /// @dev The `pendingOwner` does not have a valid handover request.
                    error NoHandoverRequest();
                    /// @dev Cannot double-initialize.
                    error AlreadyInitialized();
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                           EVENTS                           */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev The ownership is transferred from `oldOwner` to `newOwner`.
                    /// This event is intentionally kept the same as OpenZeppelin's Ownable to be
                    /// compatible with indexers and [EIP-173](https://eips.ethereum.org/EIPS/eip-173),
                    /// despite it not being as lightweight as a single argument event.
                    event OwnershipTransferred(address indexed oldOwner, address indexed newOwner);
                    /// @dev An ownership handover to `pendingOwner` has been requested.
                    event OwnershipHandoverRequested(address indexed pendingOwner);
                    /// @dev The ownership handover to `pendingOwner` has been canceled.
                    event OwnershipHandoverCanceled(address indexed pendingOwner);
                    /// @dev `keccak256(bytes("OwnershipTransferred(address,address)"))`.
                    uint256 private constant _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE =
                        0x8be0079c531659141344cd1fd0a4f28419497f9722a3daafe3b4186f6b6457e0;
                    /// @dev `keccak256(bytes("OwnershipHandoverRequested(address)"))`.
                    uint256 private constant _OWNERSHIP_HANDOVER_REQUESTED_EVENT_SIGNATURE =
                        0xdbf36a107da19e49527a7176a1babf963b4b0ff8cde35ee35d6cd8f1f9ac7e1d;
                    /// @dev `keccak256(bytes("OwnershipHandoverCanceled(address)"))`.
                    uint256 private constant _OWNERSHIP_HANDOVER_CANCELED_EVENT_SIGNATURE =
                        0xfa7b8eab7da67f412cc9575ed43464468f9bfbae89d1675917346ca6d8fe3c92;
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                          STORAGE                           */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev The owner slot is given by:
                    /// `bytes32(~uint256(uint32(bytes4(keccak256("_OWNER_SLOT_NOT")))))`.
                    /// It is intentionally chosen to be a high value
                    /// to avoid collision with lower slots.
                    /// The choice of manual storage layout is to enable compatibility
                    /// with both regular and upgradeable contracts.
                    bytes32 internal constant _OWNER_SLOT =
                        0xffffffffffffffffffffffffffffffffffffffffffffffffffffffff74873927;
                    /// The ownership handover slot of `newOwner` is given by:
                    /// ```
                    ///     mstore(0x00, or(shl(96, user), _HANDOVER_SLOT_SEED))
                    ///     let handoverSlot := keccak256(0x00, 0x20)
                    /// ```
                    /// It stores the expiry timestamp of the two-step ownership handover.
                    uint256 private constant _HANDOVER_SLOT_SEED = 0x389a75e1;
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                     INTERNAL FUNCTIONS                     */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev Override to return true to make `_initializeOwner` prevent double-initialization.
                    function _guardInitializeOwner() internal pure virtual returns (bool guard) {}
                    /// @dev Initializes the owner directly without authorization guard.
                    /// This function must be called upon initialization,
                    /// regardless of whether the contract is upgradeable or not.
                    /// This is to enable generalization to both regular and upgradeable contracts,
                    /// and to save gas in case the initial owner is not the caller.
                    /// For performance reasons, this function will not check if there
                    /// is an existing owner.
                    function _initializeOwner(address newOwner) internal virtual {
                        if (_guardInitializeOwner()) {
                            /// @solidity memory-safe-assembly
                            assembly {
                                let ownerSlot := _OWNER_SLOT
                                if sload(ownerSlot) {
                                    mstore(0x00, 0x0dc149f0) // `AlreadyInitialized()`.
                                    revert(0x1c, 0x04)
                                }
                                // Clean the upper 96 bits.
                                newOwner := shr(96, shl(96, newOwner))
                                // Store the new value.
                                sstore(ownerSlot, or(newOwner, shl(255, iszero(newOwner))))
                                // Emit the {OwnershipTransferred} event.
                                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, 0, newOwner)
                            }
                        } else {
                            /// @solidity memory-safe-assembly
                            assembly {
                                // Clean the upper 96 bits.
                                newOwner := shr(96, shl(96, newOwner))
                                // Store the new value.
                                sstore(_OWNER_SLOT, newOwner)
                                // Emit the {OwnershipTransferred} event.
                                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, 0, newOwner)
                            }
                        }
                    }
                    /// @dev Sets the owner directly without authorization guard.
                    function _setOwner(address newOwner) internal virtual {
                        if (_guardInitializeOwner()) {
                            /// @solidity memory-safe-assembly
                            assembly {
                                let ownerSlot := _OWNER_SLOT
                                // Clean the upper 96 bits.
                                newOwner := shr(96, shl(96, newOwner))
                                // Emit the {OwnershipTransferred} event.
                                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, sload(ownerSlot), newOwner)
                                // Store the new value.
                                sstore(ownerSlot, or(newOwner, shl(255, iszero(newOwner))))
                            }
                        } else {
                            /// @solidity memory-safe-assembly
                            assembly {
                                let ownerSlot := _OWNER_SLOT
                                // Clean the upper 96 bits.
                                newOwner := shr(96, shl(96, newOwner))
                                // Emit the {OwnershipTransferred} event.
                                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, sload(ownerSlot), newOwner)
                                // Store the new value.
                                sstore(ownerSlot, newOwner)
                            }
                        }
                    }
                    /// @dev Throws if the sender is not the owner.
                    function _checkOwner() internal view virtual {
                        /// @solidity memory-safe-assembly
                        assembly {
                            // If the caller is not the stored owner, revert.
                            if iszero(eq(caller(), sload(_OWNER_SLOT))) {
                                mstore(0x00, 0x82b42900) // `Unauthorized()`.
                                revert(0x1c, 0x04)
                            }
                        }
                    }
                    /// @dev Returns how long a two-step ownership handover is valid for in seconds.
                    /// Override to return a different value if needed.
                    /// Made internal to conserve bytecode. Wrap it in a public function if needed.
                    function _ownershipHandoverValidFor() internal view virtual returns (uint64) {
                        return 48 * 3600;
                    }
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                  PUBLIC UPDATE FUNCTIONS                   */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev Allows the owner to transfer the ownership to `newOwner`.
                    function transferOwnership(address newOwner) public payable virtual onlyOwner {
                        /// @solidity memory-safe-assembly
                        assembly {
                            if iszero(shl(96, newOwner)) {
                                mstore(0x00, 0x7448fbae) // `NewOwnerIsZeroAddress()`.
                                revert(0x1c, 0x04)
                            }
                        }
                        _setOwner(newOwner);
                    }
                    /// @dev Allows the owner to renounce their ownership.
                    function renounceOwnership() public payable virtual onlyOwner {
                        _setOwner(address(0));
                    }
                    /// @dev Request a two-step ownership handover to the caller.
                    /// The request will automatically expire in 48 hours (172800 seconds) by default.
                    function requestOwnershipHandover() public payable virtual {
                        unchecked {
                            uint256 expires = block.timestamp + _ownershipHandoverValidFor();
                            /// @solidity memory-safe-assembly
                            assembly {
                                // Compute and set the handover slot to `expires`.
                                mstore(0x0c, _HANDOVER_SLOT_SEED)
                                mstore(0x00, caller())
                                sstore(keccak256(0x0c, 0x20), expires)
                                // Emit the {OwnershipHandoverRequested} event.
                                log2(0, 0, _OWNERSHIP_HANDOVER_REQUESTED_EVENT_SIGNATURE, caller())
                            }
                        }
                    }
                    /// @dev Cancels the two-step ownership handover to the caller, if any.
                    function cancelOwnershipHandover() public payable virtual {
                        /// @solidity memory-safe-assembly
                        assembly {
                            // Compute and set the handover slot to 0.
                            mstore(0x0c, _HANDOVER_SLOT_SEED)
                            mstore(0x00, caller())
                            sstore(keccak256(0x0c, 0x20), 0)
                            // Emit the {OwnershipHandoverCanceled} event.
                            log2(0, 0, _OWNERSHIP_HANDOVER_CANCELED_EVENT_SIGNATURE, caller())
                        }
                    }
                    /// @dev Allows the owner to complete the two-step ownership handover to `pendingOwner`.
                    /// Reverts if there is no existing ownership handover requested by `pendingOwner`.
                    function completeOwnershipHandover(address pendingOwner) public payable virtual onlyOwner {
                        /// @solidity memory-safe-assembly
                        assembly {
                            // Compute and set the handover slot to 0.
                            mstore(0x0c, _HANDOVER_SLOT_SEED)
                            mstore(0x00, pendingOwner)
                            let handoverSlot := keccak256(0x0c, 0x20)
                            // If the handover does not exist, or has expired.
                            if gt(timestamp(), sload(handoverSlot)) {
                                mstore(0x00, 0x6f5e8818) // `NoHandoverRequest()`.
                                revert(0x1c, 0x04)
                            }
                            // Set the handover slot to 0.
                            sstore(handoverSlot, 0)
                        }
                        _setOwner(pendingOwner);
                    }
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                   PUBLIC READ FUNCTIONS                    */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev Returns the owner of the contract.
                    function owner() public view virtual returns (address result) {
                        /// @solidity memory-safe-assembly
                        assembly {
                            result := sload(_OWNER_SLOT)
                        }
                    }
                    /// @dev Returns the expiry timestamp for the two-step ownership handover to `pendingOwner`.
                    function ownershipHandoverExpiresAt(address pendingOwner)
                        public
                        view
                        virtual
                        returns (uint256 result)
                    {
                        /// @solidity memory-safe-assembly
                        assembly {
                            // Compute the handover slot.
                            mstore(0x0c, _HANDOVER_SLOT_SEED)
                            mstore(0x00, pendingOwner)
                            // Load the handover slot.
                            result := sload(keccak256(0x0c, 0x20))
                        }
                    }
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                         MODIFIERS                          */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev Marks a function as only callable by the owner.
                    modifier onlyOwner() virtual {
                        _checkOwner();
                        _;
                    }
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)
                pragma solidity ^0.8.20;
                /**
                 * @dev Interface of the ERC20 standard as defined in the EIP.
                 */
                interface IERC20 {
                    /**
                     * @dev Emitted when `value` tokens are moved from one account (`from`) to
                     * another (`to`).
                     *
                     * Note that `value` may be zero.
                     */
                    event Transfer(address indexed from, address indexed to, uint256 value);
                    /**
                     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                     * a call to {approve}. `value` is the new allowance.
                     */
                    event Approval(address indexed owner, address indexed spender, uint256 value);
                    /**
                     * @dev Returns the value of tokens in existence.
                     */
                    function totalSupply() external view returns (uint256);
                    /**
                     * @dev Returns the value of tokens owned by `account`.
                     */
                    function balanceOf(address account) external view returns (uint256);
                    /**
                     * @dev Moves a `value` amount of tokens from the caller's account to `to`.
                     *
                     * Returns a boolean value indicating whether the operation succeeded.
                     *
                     * Emits a {Transfer} event.
                     */
                    function transfer(address to, uint256 value) external returns (bool);
                    /**
                     * @dev Returns the remaining number of tokens that `spender` will be
                     * allowed to spend on behalf of `owner` through {transferFrom}. This is
                     * zero by default.
                     *
                     * This value changes when {approve} or {transferFrom} are called.
                     */
                    function allowance(address owner, address spender) external view returns (uint256);
                    /**
                     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
                     * caller's tokens.
                     *
                     * Returns a boolean value indicating whether the operation succeeded.
                     *
                     * IMPORTANT: Beware that changing an allowance with this method brings the risk
                     * that someone may use both the old and the new allowance by unfortunate
                     * transaction ordering. One possible solution to mitigate this race
                     * condition is to first reduce the spender's allowance to 0 and set the
                     * desired value afterwards:
                     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                     *
                     * Emits an {Approval} event.
                     */
                    function approve(address spender, uint256 value) external returns (bool);
                    /**
                     * @dev Moves a `value` amount of tokens from `from` to `to` using the
                     * allowance mechanism. `value` is then deducted from the caller's
                     * allowance.
                     *
                     * Returns a boolean value indicating whether the operation succeeded.
                     *
                     * Emits a {Transfer} event.
                     */
                    function transferFrom(address from, address to, uint256 value) external returns (bool);
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)
                pragma solidity ^0.8.20;
                import {IERC20} from "../IERC20.sol";
                import {IERC20Permit} from "../extensions/IERC20Permit.sol";
                import {Address} from "../../../utils/Address.sol";
                /**
                 * @title SafeERC20
                 * @dev Wrappers around ERC20 operations that throw on failure (when the token
                 * contract returns false). Tokens that return no value (and instead revert or
                 * throw on failure) are also supported, non-reverting calls are assumed to be
                 * successful.
                 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
                 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
                 */
                library SafeERC20 {
                    using Address for address;
                    /**
                     * @dev An operation with an ERC20 token failed.
                     */
                    error SafeERC20FailedOperation(address token);
                    /**
                     * @dev Indicates a failed `decreaseAllowance` request.
                     */
                    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);
                    /**
                     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
                     * non-reverting calls are assumed to be successful.
                     */
                    function safeTransfer(IERC20 token, address to, uint256 value) internal {
                        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
                    }
                    /**
                     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
                     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
                     */
                    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
                        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
                    }
                    /**
                     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
                     * non-reverting calls are assumed to be successful.
                     */
                    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                        uint256 oldAllowance = token.allowance(address(this), spender);
                        forceApprove(token, spender, oldAllowance + value);
                    }
                    /**
                     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
                     * value, non-reverting calls are assumed to be successful.
                     */
                    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
                        unchecked {
                            uint256 currentAllowance = token.allowance(address(this), spender);
                            if (currentAllowance < requestedDecrease) {
                                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
                            }
                            forceApprove(token, spender, currentAllowance - requestedDecrease);
                        }
                    }
                    /**
                     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
                     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
                     * to be set to zero before setting it to a non-zero value, such as USDT.
                     */
                    function forceApprove(IERC20 token, address spender, uint256 value) internal {
                        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));
                        if (!_callOptionalReturnBool(token, approvalCall)) {
                            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
                            _callOptionalReturn(token, approvalCall);
                        }
                    }
                    /**
                     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                     * on the return value: the return value is optional (but if data is returned, it must not be false).
                     * @param token The token targeted by the call.
                     * @param data The call data (encoded using abi.encode or one of its variants).
                     */
                    function _callOptionalReturn(IERC20 token, bytes memory data) private {
                        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
                        // the target address contains contract code and also asserts for success in the low-level call.
                        bytes memory returndata = address(token).functionCall(data);
                        if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
                            revert SafeERC20FailedOperation(address(token));
                        }
                    }
                    /**
                     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                     * on the return value: the return value is optional (but if data is returned, it must not be false).
                     * @param token The token targeted by the call.
                     * @param data The call data (encoded using abi.encode or one of its variants).
                     *
                     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
                     */
                    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
                        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
                        // and not revert is the subcall reverts.
                        (bool success, bytes memory returndata) = address(token).call(data);
                        return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.23;
                import {ISignatureTransfer} from "permit2-relay/src/interfaces/ISignatureTransfer.sol";
                interface IERC20Router {
                    function permitMulticall(
                        address user,
                        ISignatureTransfer.PermitBatchTransferFrom memory permit,
                        address[] calldata targets,
                        bytes[] calldata datas,
                        uint256[] calldata values,
                        address refundTo,
                        bytes memory permitSignature
                    ) external payable returns (bytes memory);
                    function delegatecallMulticall(
                        address[] calldata targets,
                        bytes[] calldata datas,
                        uint256[] calldata values,
                        address refundTo
                    ) external payable returns (bytes memory);
                    function cleanupERC20(address token, address refundTo) external;
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)
                pragma solidity ^0.8.20;
                /**
                 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
                 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
                 *
                 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
                 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
                 * need to send a transaction, and thus is not required to hold Ether at all.
                 *
                 * ==== Security Considerations
                 *
                 * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
                 * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
                 * considered as an intention to spend the allowance in any specific way. The second is that because permits have
                 * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
                 * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
                 * generally recommended is:
                 *
                 * ```solidity
                 * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
                 *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
                 *     doThing(..., value);
                 * }
                 *
                 * function doThing(..., uint256 value) public {
                 *     token.safeTransferFrom(msg.sender, address(this), value);
                 *     ...
                 * }
                 * ```
                 *
                 * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
                 * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
                 * {SafeERC20-safeTransferFrom}).
                 *
                 * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
                 * contracts should have entry points that don't rely on permit.
                 */
                interface IERC20Permit {
                    /**
                     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
                     * given ``owner``'s signed approval.
                     *
                     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
                     * ordering also apply here.
                     *
                     * Emits an {Approval} event.
                     *
                     * Requirements:
                     *
                     * - `spender` cannot be the zero address.
                     * - `deadline` must be a timestamp in the future.
                     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
                     * over the EIP712-formatted function arguments.
                     * - the signature must use ``owner``'s current nonce (see {nonces}).
                     *
                     * For more information on the signature format, see the
                     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
                     * section].
                     *
                     * CAUTION: See Security Considerations above.
                     */
                    function permit(
                        address owner,
                        address spender,
                        uint256 value,
                        uint256 deadline,
                        uint8 v,
                        bytes32 r,
                        bytes32 s
                    ) external;
                    /**
                     * @dev Returns the current nonce for `owner`. This value must be
                     * included whenever a signature is generated for {permit}.
                     *
                     * Every successful call to {permit} increases ``owner``'s nonce by one. This
                     * prevents a signature from being used multiple times.
                     */
                    function nonces(address owner) external view returns (uint256);
                    /**
                     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
                     */
                    // solhint-disable-next-line func-name-mixedcase
                    function DOMAIN_SEPARATOR() external view returns (bytes32);
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)
                pragma solidity ^0.8.20;
                /**
                 * @dev Collection of functions related to the address type
                 */
                library Address {
                    /**
                     * @dev The ETH balance of the account is not enough to perform the operation.
                     */
                    error AddressInsufficientBalance(address account);
                    /**
                     * @dev There's no code at `target` (it is not a contract).
                     */
                    error AddressEmptyCode(address target);
                    /**
                     * @dev A call to an address target failed. The target may have reverted.
                     */
                    error FailedInnerCall();
                    /**
                     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                     * `recipient`, forwarding all available gas and reverting on errors.
                     *
                     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                     * of certain opcodes, possibly making contracts go over the 2300 gas limit
                     * imposed by `transfer`, making them unable to receive funds via
                     * `transfer`. {sendValue} removes this limitation.
                     *
                     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                     *
                     * IMPORTANT: because control is transferred to `recipient`, care must be
                     * taken to not create reentrancy vulnerabilities. Consider using
                     * {ReentrancyGuard} or the
                     * https://solidity.readthedocs.io/en/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                     */
                    function sendValue(address payable recipient, uint256 amount) internal {
                        if (address(this).balance < amount) {
                            revert AddressInsufficientBalance(address(this));
                        }
                        (bool success, ) = recipient.call{value: amount}("");
                        if (!success) {
                            revert FailedInnerCall();
                        }
                    }
                    /**
                     * @dev Performs a Solidity function call using a low level `call`. A
                     * plain `call` is an unsafe replacement for a function call: use this
                     * function instead.
                     *
                     * If `target` reverts with a revert reason or custom error, it is bubbled
                     * up by this function (like regular Solidity function calls). However, if
                     * the call reverted with no returned reason, this function reverts with a
                     * {FailedInnerCall} error.
                     *
                     * Returns the raw returned data. To convert to the expected return value,
                     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                     *
                     * Requirements:
                     *
                     * - `target` must be a contract.
                     * - calling `target` with `data` must not revert.
                     */
                    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                        return functionCallWithValue(target, data, 0);
                    }
                    /**
                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                     * but also transferring `value` wei to `target`.
                     *
                     * Requirements:
                     *
                     * - the calling contract must have an ETH balance of at least `value`.
                     * - the called Solidity function must be `payable`.
                     */
                    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                        if (address(this).balance < value) {
                            revert AddressInsufficientBalance(address(this));
                        }
                        (bool success, bytes memory returndata) = target.call{value: value}(data);
                        return verifyCallResultFromTarget(target, success, returndata);
                    }
                    /**
                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                     * but performing a static call.
                     */
                    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                        (bool success, bytes memory returndata) = target.staticcall(data);
                        return verifyCallResultFromTarget(target, success, returndata);
                    }
                    /**
                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                     * but performing a delegate call.
                     */
                    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                        (bool success, bytes memory returndata) = target.delegatecall(data);
                        return verifyCallResultFromTarget(target, success, returndata);
                    }
                    /**
                     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
                     * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
                     * unsuccessful call.
                     */
                    function verifyCallResultFromTarget(
                        address target,
                        bool success,
                        bytes memory returndata
                    ) internal view returns (bytes memory) {
                        if (!success) {
                            _revert(returndata);
                        } else {
                            // only check if target is a contract if the call was successful and the return data is empty
                            // otherwise we already know that it was a contract
                            if (returndata.length == 0 && target.code.length == 0) {
                                revert AddressEmptyCode(target);
                            }
                            return returndata;
                        }
                    }
                    /**
                     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
                     * revert reason or with a default {FailedInnerCall} error.
                     */
                    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
                        if (!success) {
                            _revert(returndata);
                        } else {
                            return returndata;
                        }
                    }
                    /**
                     * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
                     */
                    function _revert(bytes memory returndata) private pure {
                        // Look for revert reason and bubble it up if present
                        if (returndata.length > 0) {
                            // The easiest way to bubble the revert reason is using memory via assembly
                            /// @solidity memory-safe-assembly
                            assembly {
                                let returndata_size := mload(returndata)
                                revert(add(32, returndata), returndata_size)
                            }
                        } else {
                            revert FailedInnerCall();
                        }
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                import {IEIP712} from "./IEIP712.sol";
                /// @title SignatureTransfer
                /// @notice Handles ERC20 token transfers through signature based actions
                /// @dev Requires user's token approval on the Permit2 contract
                interface ISignatureTransfer is IEIP712 {
                    /// @notice Thrown when the requested amount for a transfer is larger than the permissioned amount
                    /// @param maxAmount The maximum amount a spender can request to transfer
                    error InvalidAmount(uint256 maxAmount);
                    /// @notice Thrown when the number of tokens permissioned to a spender does not match the number of tokens being transferred
                    /// @dev If the spender does not need to transfer the number of tokens permitted, the spender can request amount 0 to be transferred
                    error LengthMismatch();
                    /// @notice Emits an event when the owner successfully invalidates an unordered nonce.
                    event UnorderedNonceInvalidation(address indexed owner, uint256 word, uint256 mask);
                    /// @notice The token and amount details for a transfer signed in the permit transfer signature
                    struct TokenPermissions {
                        // ERC20 token address
                        address token;
                        // the maximum amount that can be spent
                        uint256 amount;
                    }
                    /// @notice The signed permit message for a single token transfer
                    struct PermitTransferFrom {
                        TokenPermissions permitted;
                        // a unique value for every token owner's signature to prevent signature replays
                        uint256 nonce;
                        // deadline on the permit signature
                        uint256 deadline;
                    }
                    /// @notice Specifies the recipient address and amount for batched transfers.
                    /// @dev Recipients and amounts correspond to the index of the signed token permissions array.
                    /// @dev Reverts if the requested amount is greater than the permitted signed amount.
                    struct SignatureTransferDetails {
                        // recipient address
                        address to;
                        // spender requested amount
                        uint256 requestedAmount;
                    }
                    /// @notice Used to reconstruct the signed permit message for multiple token transfers
                    /// @dev Do not need to pass in spender address as it is required that it is msg.sender
                    /// @dev Note that a user still signs over a spender address
                    struct PermitBatchTransferFrom {
                        // the tokens and corresponding amounts permitted for a transfer
                        TokenPermissions[] permitted;
                        // a unique value for every token owner's signature to prevent signature replays
                        uint256 nonce;
                        // deadline on the permit signature
                        uint256 deadline;
                    }
                    /// @notice A map from token owner address and a caller specified word index to a bitmap. Used to set bits in the bitmap to prevent against signature replay protection
                    /// @dev Uses unordered nonces so that permit messages do not need to be spent in a certain order
                    /// @dev The mapping is indexed first by the token owner, then by an index specified in the nonce
                    /// @dev It returns a uint256 bitmap
                    /// @dev The index, or wordPosition is capped at type(uint248).max
                    function nonceBitmap(address, uint256) external view returns (uint256);
                    /// @notice Transfers a token using a signed permit message
                    /// @dev Reverts if the requested amount is greater than the permitted signed amount
                    /// @param permit The permit data signed over by the owner
                    /// @param owner The owner of the tokens to transfer
                    /// @param transferDetails The spender's requested transfer details for the permitted token
                    /// @param signature The signature to verify
                    function permitTransferFrom(
                        PermitTransferFrom memory permit,
                        SignatureTransferDetails calldata transferDetails,
                        address owner,
                        bytes calldata signature
                    ) external;
                    /// @notice Transfers a token using a signed permit message
                    /// @notice Includes extra data provided by the caller to verify signature over
                    /// @dev The witness type string must follow EIP712 ordering of nested structs and must include the TokenPermissions type definition
                    /// @dev Reverts if the requested amount is greater than the permitted signed amount
                    /// @param permit The permit data signed over by the owner
                    /// @param owner The owner of the tokens to transfer
                    /// @param transferDetails The spender's requested transfer details for the permitted token
                    /// @param witness Extra data to include when checking the user signature
                    /// @param witnessTypeString The EIP-712 type definition for remaining string stub of the typehash
                    /// @param signature The signature to verify
                    function permitWitnessTransferFrom(
                        PermitTransferFrom memory permit,
                        SignatureTransferDetails calldata transferDetails,
                        address owner,
                        bytes32 witness,
                        string calldata witnessTypeString,
                        bytes calldata signature
                    ) external;
                    /// @notice Transfers multiple tokens using a signed permit message
                    /// @param permit The permit data signed over by the owner
                    /// @param owner The owner of the tokens to transfer
                    /// @param transferDetails Specifies the recipient and requested amount for the token transfer
                    /// @param signature The signature to verify
                    function permitTransferFrom(
                        PermitBatchTransferFrom memory permit,
                        SignatureTransferDetails[] calldata transferDetails,
                        address owner,
                        bytes calldata signature
                    ) external;
                    /// @notice Transfers multiple tokens using a signed permit message
                    /// @dev The witness type string must follow EIP712 ordering of nested structs and must include the TokenPermissions type definition
                    /// @notice Includes extra data provided by the caller to verify signature over
                    /// @param permit The permit data signed over by the owner
                    /// @param owner The owner of the tokens to transfer
                    /// @param transferDetails Specifies the recipient and requested amount for the token transfer
                    /// @param witness Extra data to include when checking the user signature
                    /// @param witnessTypeString The EIP-712 type definition for remaining string stub of the typehash
                    /// @param signature The signature to verify
                    function permitWitnessTransferFrom(
                        PermitBatchTransferFrom memory permit,
                        SignatureTransferDetails[] calldata transferDetails,
                        address owner,
                        bytes32 witness,
                        string calldata witnessTypeString,
                        bytes calldata signature
                    ) external;
                    /// @notice Invalidates the bits specified in mask for the bitmap at the word position
                    /// @dev The wordPos is maxed at type(uint248).max
                    /// @param wordPos A number to index the nonceBitmap at
                    /// @param mask A bitmap masked against msg.sender's current bitmap at the word position
                    function invalidateUnorderedNonces(uint256 wordPos, uint256 mask) external;
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                interface IEIP712 {
                    function DOMAIN_SEPARATOR() external view returns (bytes32);
                }
                

                File 2 of 7: ERC20Router
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.25;
                import {Ownable} from "solady/src/auth/Ownable.sol";
                import {Tstorish} from "tstorish/src/Tstorish.sol";
                import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                import {IERC721} from "@openzeppelin/contracts/token/ERC721/IERC721.sol";
                import {IERC1155} from "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";
                import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
                import {IAllowanceTransfer} from "permit2-relay/src/interfaces/IAllowanceTransfer.sol";
                import {ISignatureTransfer} from "permit2-relay/src/interfaces/ISignatureTransfer.sol";
                import {IPermit2} from "permit2-relay/src/interfaces/IPermit2.sol";
                import {RelayerWitness} from "./types/lib/RelayStructs.sol";
                import {IMulticaller} from "./types/interfaces/IMulticaller.sol";
                contract ERC20Router is Ownable, Tstorish {
                    using SafeERC20 for IERC20;
                    // --- Errors --- //
                    /// @notice Revert if array lengths do not match
                    error ArrayLengthsMismatch();
                    /// @notice Revert if this contract is set as the recipient
                    error InvalidRecipient(address recipient);
                    /// @notice Revert if the target is invalid
                    error InvalidTarget(address target);
                    /// @notice Revert if the native transfer failed
                    error NativeTransferFailed();
                    /// @notice Revert if no recipient is set
                    error NoRecipientSet();
                    uint256 RECIPIENT_STORAGE_SLOT = uint256(keccak256("ERC20Router.recipient"));
                    address constant ZORA_REWARDS_V1 =
                        0x7777777F279eba3d3Ad8F4E708545291A6fDBA8B;
                    IPermit2 private immutable PERMIT2;
                    address private immutable MULTICALLER;
                    string public constant _RELAYER_WITNESS_TYPE_STRING =
                        "RelayerWitness witness)RelayerWitness(address relayer)TokenPermissions(address token,uint256 amount)";
                    bytes32 public constant _EIP_712_RELAYER_WITNESS_TYPE_HASH =
                        keccak256("RelayerWitness(address relayer)");
                    constructor(address permit2, address multicaller, address owner) Tstorish() {
                        // Set the address of the Permit2 contract
                        PERMIT2 = IPermit2(permit2);
                        // Set the address of the multicaller contract
                        MULTICALLER = multicaller;
                        // Set the owner that can withdraw funds stuck in the contract
                        _initializeOwner(owner);
                    }
                    receive() external payable {}
                    function withdraw() external onlyOwner {
                        _send(msg.sender, address(this).balance);
                    }
                    /// @notice Pull user ERC20 tokens through a signed batch permit
                    ///         and perform an arbitrary multicall. Pass in an empty
                    ///         permitSignature to only perform the multicall.
                    /// @dev msg.value will persist across all calls in the multicall
                    /// @param user The address of the user
                    /// @param permit The permit details
                    /// @param targets The addresses of the contracts to call
                    /// @param datas The calldata for each call
                    /// @param values The value to send with each call
                    /// @param refundTo The address to refund any leftover ETH to
                    /// @param permitSignature The signature for the permit
                    function permitMulticall(
                        address user,
                        ISignatureTransfer.PermitBatchTransferFrom memory permit,
                        address[] calldata targets,
                        bytes[] calldata datas,
                        uint256[] calldata values,
                        address refundTo,
                        bytes memory permitSignature
                    ) external payable returns (bytes memory) {
                        // Revert if array lengths do not match
                        if (targets.length != datas.length || datas.length != values.length) {
                            revert ArrayLengthsMismatch();
                        }
                        if (permitSignature.length != 0) {
                            // Use permit to transfer tokens from user to router
                            _handlePermitBatch(user, permit, permitSignature);
                        }
                        // Perform the multicall and send leftover to refundTo
                        bytes memory data = _delegatecallMulticall(
                            targets,
                            datas,
                            values,
                            refundTo
                        );
                        return data;
                    }
                    /// @notice Call the Multicaller with a delegatecall to set the ERC20Router as the
                    ///         sender of the calls to the targets.
                    /// @dev    If a multicall is expecting to mint ERC721s or ERC1155s, the recipient must be explicitly set
                    ///         All calls to ERC721s and ERC1155s in the multicall will have the same recipient set in refundTo
                    ///         If refundTo is address(this), be sure to transfer tokens out of the router as part of the multicall
                    /// @param targets The addresses of the contracts to call
                    /// @param datas The calldata for each call
                    /// @param values The value to send with each call
                    /// @param refundTo The address to send any leftover ETH and set as recipient of ERC721/ERC1155 mints
                    function delegatecallMulticall(
                        address[] calldata targets,
                        bytes[] calldata datas,
                        uint256[] calldata values,
                        address refundTo
                    ) external payable returns (bytes memory) {
                        // Revert if array lengths do not match
                        if (targets.length != datas.length || datas.length != values.length) {
                            revert ArrayLengthsMismatch();
                        }
                        // Set the recipient in storage
                        _setRecipient(refundTo);
                        // Perform the multicall
                        bytes memory data = _delegatecallMulticall(
                            targets,
                            datas,
                            values,
                            refundTo
                        );
                        // Clear the recipient in storage
                        _clearRecipient();
                        return data;
                    }
                    /// @notice Send leftover ERC20 tokens to the refundTo address
                    /// @dev Should be included in the multicall if the router is expecting to receive tokens
                    /// @param token The address of the ERC20 token
                    /// @param refundTo The address to refund the tokens to
                    function cleanupERC20(address token, address refundTo) external {
                        // Check the router's balance for the token
                        uint256 balance = IERC20(token).balanceOf(address(this));
                        // Transfer the token to the refundTo address
                        if (balance > 0) {
                            IERC20(token).safeTransfer(refundTo, balance);
                        }
                    }
                    /// @notice Internal function to handle a permit batch transfer
                    /// @param user The address of the user
                    /// @param permit The permit details
                    /// @param permitSignature The signature for the permit
                    function _handlePermitBatch(
                        address user,
                        ISignatureTransfer.PermitBatchTransferFrom memory permit,
                        bytes memory permitSignature
                    ) internal {
                        // Create the witness that should be signed over
                        bytes32 witness = keccak256(
                            abi.encode(_EIP_712_RELAYER_WITNESS_TYPE_HASH, msg.sender)
                        );
                        // Create the SignatureTransferDetails array
                        ISignatureTransfer.SignatureTransferDetails[]
                            memory signatureTransferDetails = new ISignatureTransfer.SignatureTransferDetails[](
                                permit.permitted.length
                            );
                        for (uint256 i = 0; i < permit.permitted.length; i++) {
                            uint256 amount = permit.permitted[i].amount;
                            signatureTransferDetails[i] = ISignatureTransfer
                                .SignatureTransferDetails({
                                    to: address(this),
                                    requestedAmount: amount
                                });
                        }
                        // Use the SignatureTransferDetails and permit signature to transfer tokens to the router
                        PERMIT2.permitWitnessTransferFrom(
                            permit,
                            signatureTransferDetails,
                            // When using a permit signature, cannot deposit on behalf of someone else other than `user`
                            user,
                            witness,
                            _RELAYER_WITNESS_TYPE_STRING,
                            permitSignature
                        );
                    }
                    /// @notice Internal function to set the recipient address for ERC721 or ERC1155 mint
                    /// @dev If the chain does not support tstore, recipient will be saved in storage
                    /// @param recipient The address of the recipient
                    function _setRecipient(address recipient) internal {
                        // Return early if the recipient is address(0) or address(1), which are special cases for the multicaller
                        // If a multicall is expecting to mint ERC721s or ERC1155s, the recipient must be explicitly set
                        if (recipient == address(0) || recipient == address(1)) {
                            return;
                        }
                        // For safety, revert if the recipient is this contract
                        // Tokens should either be minted directly to recipient, or transferred to recipient through the onReceived hooks
                        if (recipient == address(this)) {
                            revert InvalidRecipient(address(this));
                        }
                        // Set the recipient in storage
                        _setTstorish(RECIPIENT_STORAGE_SLOT, uint256(uint160(recipient)));
                    }
                    /// @notice Internal function to get the recipient address for ERC721 or ERC1155 mint
                    function _getRecipient() internal view returns (address) {
                        // Get the recipient from storage
                        return address(uint160(_getTstorish(RECIPIENT_STORAGE_SLOT)));
                    }
                    /// @notice Internal function to clear the recipient address for ERC721 or ERC1155 mint
                    function _clearRecipient() internal {
                        // Return if recipient hasn't been set
                        if (_getRecipient() == address(0)) {
                            return;
                        }
                        // Clear the recipient in storage
                        _clearTstorish(RECIPIENT_STORAGE_SLOT);
                    }
                    /// @notice Internal function to delegatecall the Multicaller contract
                    /// @param targets The addresses of the contracts to call
                    /// @param datas The calldata for each call
                    /// @param values The value to send with each call
                    /// @param refundTo The address to send any leftover ETH and set as recipient of ERC721/ERC1155 mints
                    function _delegatecallMulticall(
                        address[] calldata targets,
                        bytes[] calldata datas,
                        uint256[] calldata values,
                        address refundTo
                    ) internal returns (bytes memory) {
                        for (uint256 i = 0; i < targets.length; i++) {
                            // Revert if the call fails
                            if (targets[i] == ZORA_REWARDS_V1) {
                                revert InvalidTarget(ZORA_REWARDS_V1);
                            }
                        }
                        // Perform the multicall and refund to the user
                        (bool success, bytes memory data) = MULTICALLER.delegatecall(
                            abi.encodeWithSignature(
                                "aggregate(address[],bytes[],uint256[],address)",
                                targets,
                                datas,
                                values,
                                refundTo
                            )
                        );
                        if (!success) {
                            assembly {
                                let returnDataSize := mload(data)
                                revert(add(data, 32), returnDataSize)
                            }
                        }
                        return data;
                    }
                    function _send(address to, uint256 value) internal {
                        bool success;
                        assembly {
                            // Save gas by avoiding copying the return data to memory.
                            // Provide at most 100k gas to the internal call, which is
                            // more than enough to cover common use-cases of logic for
                            // receiving native tokens (eg. SCW payable fallbacks).
                            success := call(100000, to, value, 0, 0, 0, 0)
                        }
                        if (!success) {
                            revert NativeTransferFailed();
                        }
                    }
                    function onERC721Received(
                        address /*_operator*/,
                        address /*_from*/,
                        uint256 _tokenId,
                        bytes calldata _data
                    ) external returns (bytes4) {
                        // Get the recipient from storage
                        address recipient = _getRecipient();
                        // Revert if no recipient is set
                        // Note this means transferring NFTs to this contract via `safeTransferFrom` will revert,
                        // unless the transfer is part of a multicall that sets the recipient in storage
                        if (recipient == address(0)) {
                            revert NoRecipientSet();
                        }
                        // Transfer the NFT to the recipient
                        IERC721(msg.sender).safeTransferFrom(address(this), recipient, _tokenId, _data);
                        return this.onERC721Received.selector;
                    }
                    function onERC1155Received(
                        address /*_operator*/,
                        address /*_from*/,
                        uint256 _id,
                        uint256 _value,
                        bytes calldata _data
                    ) external returns (bytes4) {
                        // Get the recipient from storage
                        address recipient = _getRecipient();
                        // Revert if no recipient is set
                        // Note this means transferring NFTs to this contract via `safeTransferFrom` will revert,
                        // unless the transfer is part of a multicall that sets the recipient in storage
                        if (recipient == address(0)) {
                            revert NoRecipientSet();
                        }
                        // Transfer the tokens to the recipient
                        IERC1155(msg.sender).safeTransferFrom(address(this), recipient, _id, _value, _data);
                        return this.onERC1155Received.selector;
                    }
                    function onERC1155BatchReceived(
                        address /*_operator*/,
                        address /*_from*/,
                        uint256[] calldata _ids,
                        uint256[] calldata _values,
                        bytes calldata _data
                    ) external returns (bytes4) {
                        // Get the recipient from storage
                        address recipient = _getRecipient();
                        // Revert if no recipient is set
                        // Note this means transferring NFTs to this contract via `safeTransferFrom` will revert,
                        // unless the transfer is part of a multicall that sets the recipient in storage
                        if (recipient == address(0)) {
                            revert NoRecipientSet();
                        }
                        // Transfer the tokens to the recipient
                        IERC1155(msg.sender).safeBatchTransferFrom(address(this), recipient, _ids, _values, _data);
                        return this.onERC1155BatchReceived.selector;
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.4;
                /// @notice Simple single owner authorization mixin.
                /// @author Solady (https://github.com/vectorized/solady/blob/main/src/auth/Ownable.sol)
                ///
                /// @dev Note:
                /// This implementation does NOT auto-initialize the owner to `msg.sender`.
                /// You MUST call the `_initializeOwner` in the constructor / initializer.
                ///
                /// While the ownable portion follows
                /// [EIP-173](https://eips.ethereum.org/EIPS/eip-173) for compatibility,
                /// the nomenclature for the 2-step ownership handover may be unique to this codebase.
                abstract contract Ownable {
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                       CUSTOM ERRORS                        */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev The caller is not authorized to call the function.
                    error Unauthorized();
                    /// @dev The `newOwner` cannot be the zero address.
                    error NewOwnerIsZeroAddress();
                    /// @dev The `pendingOwner` does not have a valid handover request.
                    error NoHandoverRequest();
                    /// @dev Cannot double-initialize.
                    error AlreadyInitialized();
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                           EVENTS                           */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev The ownership is transferred from `oldOwner` to `newOwner`.
                    /// This event is intentionally kept the same as OpenZeppelin's Ownable to be
                    /// compatible with indexers and [EIP-173](https://eips.ethereum.org/EIPS/eip-173),
                    /// despite it not being as lightweight as a single argument event.
                    event OwnershipTransferred(address indexed oldOwner, address indexed newOwner);
                    /// @dev An ownership handover to `pendingOwner` has been requested.
                    event OwnershipHandoverRequested(address indexed pendingOwner);
                    /// @dev The ownership handover to `pendingOwner` has been canceled.
                    event OwnershipHandoverCanceled(address indexed pendingOwner);
                    /// @dev `keccak256(bytes("OwnershipTransferred(address,address)"))`.
                    uint256 private constant _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE =
                        0x8be0079c531659141344cd1fd0a4f28419497f9722a3daafe3b4186f6b6457e0;
                    /// @dev `keccak256(bytes("OwnershipHandoverRequested(address)"))`.
                    uint256 private constant _OWNERSHIP_HANDOVER_REQUESTED_EVENT_SIGNATURE =
                        0xdbf36a107da19e49527a7176a1babf963b4b0ff8cde35ee35d6cd8f1f9ac7e1d;
                    /// @dev `keccak256(bytes("OwnershipHandoverCanceled(address)"))`.
                    uint256 private constant _OWNERSHIP_HANDOVER_CANCELED_EVENT_SIGNATURE =
                        0xfa7b8eab7da67f412cc9575ed43464468f9bfbae89d1675917346ca6d8fe3c92;
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                          STORAGE                           */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev The owner slot is given by:
                    /// `bytes32(~uint256(uint32(bytes4(keccak256("_OWNER_SLOT_NOT")))))`.
                    /// It is intentionally chosen to be a high value
                    /// to avoid collision with lower slots.
                    /// The choice of manual storage layout is to enable compatibility
                    /// with both regular and upgradeable contracts.
                    bytes32 internal constant _OWNER_SLOT =
                        0xffffffffffffffffffffffffffffffffffffffffffffffffffffffff74873927;
                    /// The ownership handover slot of `newOwner` is given by:
                    /// ```
                    ///     mstore(0x00, or(shl(96, user), _HANDOVER_SLOT_SEED))
                    ///     let handoverSlot := keccak256(0x00, 0x20)
                    /// ```
                    /// It stores the expiry timestamp of the two-step ownership handover.
                    uint256 private constant _HANDOVER_SLOT_SEED = 0x389a75e1;
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                     INTERNAL FUNCTIONS                     */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev Override to return true to make `_initializeOwner` prevent double-initialization.
                    function _guardInitializeOwner() internal pure virtual returns (bool guard) {}
                    /// @dev Initializes the owner directly without authorization guard.
                    /// This function must be called upon initialization,
                    /// regardless of whether the contract is upgradeable or not.
                    /// This is to enable generalization to both regular and upgradeable contracts,
                    /// and to save gas in case the initial owner is not the caller.
                    /// For performance reasons, this function will not check if there
                    /// is an existing owner.
                    function _initializeOwner(address newOwner) internal virtual {
                        if (_guardInitializeOwner()) {
                            /// @solidity memory-safe-assembly
                            assembly {
                                let ownerSlot := _OWNER_SLOT
                                if sload(ownerSlot) {
                                    mstore(0x00, 0x0dc149f0) // `AlreadyInitialized()`.
                                    revert(0x1c, 0x04)
                                }
                                // Clean the upper 96 bits.
                                newOwner := shr(96, shl(96, newOwner))
                                // Store the new value.
                                sstore(ownerSlot, or(newOwner, shl(255, iszero(newOwner))))
                                // Emit the {OwnershipTransferred} event.
                                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, 0, newOwner)
                            }
                        } else {
                            /// @solidity memory-safe-assembly
                            assembly {
                                // Clean the upper 96 bits.
                                newOwner := shr(96, shl(96, newOwner))
                                // Store the new value.
                                sstore(_OWNER_SLOT, newOwner)
                                // Emit the {OwnershipTransferred} event.
                                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, 0, newOwner)
                            }
                        }
                    }
                    /// @dev Sets the owner directly without authorization guard.
                    function _setOwner(address newOwner) internal virtual {
                        if (_guardInitializeOwner()) {
                            /// @solidity memory-safe-assembly
                            assembly {
                                let ownerSlot := _OWNER_SLOT
                                // Clean the upper 96 bits.
                                newOwner := shr(96, shl(96, newOwner))
                                // Emit the {OwnershipTransferred} event.
                                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, sload(ownerSlot), newOwner)
                                // Store the new value.
                                sstore(ownerSlot, or(newOwner, shl(255, iszero(newOwner))))
                            }
                        } else {
                            /// @solidity memory-safe-assembly
                            assembly {
                                let ownerSlot := _OWNER_SLOT
                                // Clean the upper 96 bits.
                                newOwner := shr(96, shl(96, newOwner))
                                // Emit the {OwnershipTransferred} event.
                                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, sload(ownerSlot), newOwner)
                                // Store the new value.
                                sstore(ownerSlot, newOwner)
                            }
                        }
                    }
                    /// @dev Throws if the sender is not the owner.
                    function _checkOwner() internal view virtual {
                        /// @solidity memory-safe-assembly
                        assembly {
                            // If the caller is not the stored owner, revert.
                            if iszero(eq(caller(), sload(_OWNER_SLOT))) {
                                mstore(0x00, 0x82b42900) // `Unauthorized()`.
                                revert(0x1c, 0x04)
                            }
                        }
                    }
                    /// @dev Returns how long a two-step ownership handover is valid for in seconds.
                    /// Override to return a different value if needed.
                    /// Made internal to conserve bytecode. Wrap it in a public function if needed.
                    function _ownershipHandoverValidFor() internal view virtual returns (uint64) {
                        return 48 * 3600;
                    }
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                  PUBLIC UPDATE FUNCTIONS                   */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev Allows the owner to transfer the ownership to `newOwner`.
                    function transferOwnership(address newOwner) public payable virtual onlyOwner {
                        /// @solidity memory-safe-assembly
                        assembly {
                            if iszero(shl(96, newOwner)) {
                                mstore(0x00, 0x7448fbae) // `NewOwnerIsZeroAddress()`.
                                revert(0x1c, 0x04)
                            }
                        }
                        _setOwner(newOwner);
                    }
                    /// @dev Allows the owner to renounce their ownership.
                    function renounceOwnership() public payable virtual onlyOwner {
                        _setOwner(address(0));
                    }
                    /// @dev Request a two-step ownership handover to the caller.
                    /// The request will automatically expire in 48 hours (172800 seconds) by default.
                    function requestOwnershipHandover() public payable virtual {
                        unchecked {
                            uint256 expires = block.timestamp + _ownershipHandoverValidFor();
                            /// @solidity memory-safe-assembly
                            assembly {
                                // Compute and set the handover slot to `expires`.
                                mstore(0x0c, _HANDOVER_SLOT_SEED)
                                mstore(0x00, caller())
                                sstore(keccak256(0x0c, 0x20), expires)
                                // Emit the {OwnershipHandoverRequested} event.
                                log2(0, 0, _OWNERSHIP_HANDOVER_REQUESTED_EVENT_SIGNATURE, caller())
                            }
                        }
                    }
                    /// @dev Cancels the two-step ownership handover to the caller, if any.
                    function cancelOwnershipHandover() public payable virtual {
                        /// @solidity memory-safe-assembly
                        assembly {
                            // Compute and set the handover slot to 0.
                            mstore(0x0c, _HANDOVER_SLOT_SEED)
                            mstore(0x00, caller())
                            sstore(keccak256(0x0c, 0x20), 0)
                            // Emit the {OwnershipHandoverCanceled} event.
                            log2(0, 0, _OWNERSHIP_HANDOVER_CANCELED_EVENT_SIGNATURE, caller())
                        }
                    }
                    /// @dev Allows the owner to complete the two-step ownership handover to `pendingOwner`.
                    /// Reverts if there is no existing ownership handover requested by `pendingOwner`.
                    function completeOwnershipHandover(address pendingOwner) public payable virtual onlyOwner {
                        /// @solidity memory-safe-assembly
                        assembly {
                            // Compute and set the handover slot to 0.
                            mstore(0x0c, _HANDOVER_SLOT_SEED)
                            mstore(0x00, pendingOwner)
                            let handoverSlot := keccak256(0x0c, 0x20)
                            // If the handover does not exist, or has expired.
                            if gt(timestamp(), sload(handoverSlot)) {
                                mstore(0x00, 0x6f5e8818) // `NoHandoverRequest()`.
                                revert(0x1c, 0x04)
                            }
                            // Set the handover slot to 0.
                            sstore(handoverSlot, 0)
                        }
                        _setOwner(pendingOwner);
                    }
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                   PUBLIC READ FUNCTIONS                    */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev Returns the owner of the contract.
                    function owner() public view virtual returns (address result) {
                        /// @solidity memory-safe-assembly
                        assembly {
                            result := sload(_OWNER_SLOT)
                        }
                    }
                    /// @dev Returns the expiry timestamp for the two-step ownership handover to `pendingOwner`.
                    function ownershipHandoverExpiresAt(address pendingOwner)
                        public
                        view
                        virtual
                        returns (uint256 result)
                    {
                        /// @solidity memory-safe-assembly
                        assembly {
                            // Compute the handover slot.
                            mstore(0x0c, _HANDOVER_SLOT_SEED)
                            mstore(0x00, pendingOwner)
                            // Load the handover slot.
                            result := sload(keccak256(0x0c, 0x20))
                        }
                    }
                    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
                    /*                         MODIFIERS                          */
                    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
                    /// @dev Marks a function as only callable by the owner.
                    modifier onlyOwner() virtual {
                        _checkOwner();
                        _;
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.24;
                contract Tstorish {
                    // Declare a storage variable indicating if TSTORE support has been
                    // activated post-deployment.
                    bool private _tstoreSupport;
                    /*
                     * ------------------------------------------------------------------------+
                     * Opcode      | Mnemonic         | Stack              | Memory            |
                     * ------------------------------------------------------------------------|
                     * 60 0x02     | PUSH1 0x02       | 0x02               |                   |
                     * 60 0x1e     | PUSH1 0x1e       | 0x1e 0x02          |                   |
                     * 61 0x3d5c   | PUSH2 0x3d5c     | 0x3d5c 0x1e 0x02   |                   |
                     * 3d          | RETURNDATASIZE   | 0 0x3d5c 0x1e 0x02 |                   |
                     *                                                                         |
                     * :: store deployed bytecode in memory: (3d) RETURNDATASIZE (5c) TLOAD :: |
                     * 52          | MSTORE           | 0x1e 0x02          | [0..0x20): 0x3d5c |
                     * f3          | RETURN           |                    | [0..0x20): 0x3d5c |
                     * ------------------------------------------------------------------------+
                     */
                    uint256 constant _TLOAD_TEST_PAYLOAD = 0x6002_601e_613d5c_3d_52_f3;
                    uint256 constant _TLOAD_TEST_PAYLOAD_LENGTH = 0x0a;
                    uint256 constant _TLOAD_TEST_PAYLOAD_OFFSET = 0x16;
                    // Declare an immutable variable to store the tstore test contract address.
                    address private immutable _tloadTestContract;
                    // Declare an immutable variable to store the initial TSTORE support status.
                    bool private immutable _tstoreInitialSupport;
                    // Declare an immutable function type variable for the _setTstorish function
                    // based on chain support for tstore at time of deployment.
                    function(uint256,uint256) internal immutable _setTstorish;
                    // Declare an immutable function type variable for the _getTstorish function
                    // based on chain support for tstore at time of deployment.
                    function(uint256) view returns (uint256) internal immutable _getTstorish;
                    // Declare an immutable function type variable for the _clearTstorish function
                    // based on chain support for tstore at time of deployment.
                    function(uint256) internal immutable _clearTstorish;
                    // Declare a few custom revert error types.
                    error TStoreAlreadyActivated();
                    error TStoreNotSupported();
                    error TloadTestContractDeploymentFailed();
                    error OnlyDirectCalls();
                    /**
                     * @dev Determine TSTORE availability during deployment. This involves
                     *      attempting to deploy a contract that utilizes TLOAD as part of the
                     *      contract construction bytecode, and configuring initial support for
                     *      using TSTORE in place of SSTORE based on the result.
                     */
                    constructor() {
                        // Deploy the contract testing TLOAD support and store the address.
                        address tloadTestContract = _prepareTloadTest();
                        // Ensure the deployment was successful.
                        if (tloadTestContract == address(0)) {
                            revert TloadTestContractDeploymentFailed();
                        }
                        // Determine if TSTORE is supported.
                        bool tstoreInitialSupport = _testTload(tloadTestContract);
                        if (tstoreInitialSupport) {
                            // If TSTORE is supported, set functions to their versions that use
                            // tstore/tload directly without support checks.
                            _setTstorish = _setTstore;
                            _getTstorish = _getTstore;
                            _clearTstorish = _clearTstore;
                        } else {
                            // If TSTORE is not supported, set functions to their versions that 
                            // fallback to sstore/sload until _tstoreSupport is true.
                            _setTstorish = _setTstorishWithSstoreFallback;
                            _getTstorish = _getTstorishWithSloadFallback;
                            _clearTstorish = _clearTstorishWithSstoreFallback;
                        }
                        _tstoreInitialSupport = tstoreInitialSupport;
                        // Set the address of the deployed TLOAD test contract as an immutable.
                        _tloadTestContract = tloadTestContract;
                    }
                    /**
                     * @dev External function to activate TSTORE usage. Does not need to be
                     *      called if TSTORE is supported from deployment, and only needs to be
                     *      called once. Reverts if TSTORE has already been activated or if the
                     *      opcode is not available. Note that this must be called directly from
                     *      an externally-owned account to avoid potential reentrancy issues.
                     */
                    function __activateTstore() external {
                        // Ensure this function is triggered from an externally-owned account.
                        if (msg.sender != tx.origin) {
                            revert OnlyDirectCalls();
                        }
                        // Determine if TSTORE can potentially be activated.
                        if (_tstoreInitialSupport || _tstoreSupport) {
                            revert TStoreAlreadyActivated();
                        }
                        // Determine if TSTORE can be activated and revert if not.
                        if (!_testTload(_tloadTestContract)) {
                            revert TStoreNotSupported();
                        }
                        // Mark TSTORE as activated.
                        _tstoreSupport = true;
                    }
                    /**
                     * @dev Private function to set a TSTORISH value. Assigned to _setTstorish 
                     *      internal function variable at construction if chain has tstore support.
                     *
                     * @param storageSlot The slot to write the TSTORISH value to.
                     * @param value       The value to write to the given storage slot.
                     */
                    function _setTstore(uint256 storageSlot, uint256 value) private {
                        assembly {
                            tstore(storageSlot, value)
                        }
                    }
                    /**
                     * @dev Private function to set a TSTORISH value with sstore fallback. 
                     *      Assigned to _setTstorish internal function variable at construction
                     *      if chain does not have tstore support.
                     *
                     * @param storageSlot The slot to write the TSTORISH value to.
                     * @param value       The value to write to the given storage slot.
                     */
                    function _setTstorishWithSstoreFallback(uint256 storageSlot, uint256 value) private {
                        if (_tstoreSupport) {
                            assembly {
                                tstore(storageSlot, value)
                            }
                        } else {
                            assembly {
                                sstore(storageSlot, value)
                            }
                        }
                    }
                    /**
                     * @dev Private function to read a TSTORISH value. Assigned to _getTstorish
                     *      internal function variable at construction if chain has tstore support.
                     *
                     * @param storageSlot The slot to read the TSTORISH value from.
                     *
                     * @return value The TSTORISH value at the given storage slot.
                     */
                    function _getTstore(
                        uint256 storageSlot
                    ) private view returns (uint256 value) {
                        assembly {
                            value := tload(storageSlot)
                        }
                    }
                    /**
                     * @dev Private function to read a TSTORISH value with sload fallback. 
                     *      Assigned to _getTstorish internal function variable at construction
                     *      if chain does not have tstore support.
                     *
                     * @param storageSlot The slot to read the TSTORISH value from.
                     *
                     * @return value The TSTORISH value at the given storage slot.
                     */
                    function _getTstorishWithSloadFallback(
                        uint256 storageSlot
                    ) private view returns (uint256 value) {
                        if (_tstoreSupport) {
                            assembly {
                                value := tload(storageSlot)
                            }
                        } else {
                            assembly {
                                value := sload(storageSlot)
                            }
                        }
                    }
                    /**
                     * @dev Private function to clear a TSTORISH value. Assigned to _clearTstorish internal 
                     *      function variable at construction if chain has tstore support.
                     *
                     * @param storageSlot The slot to clear the TSTORISH value for.
                     */
                    function _clearTstore(uint256 storageSlot) private {
                        assembly {
                            tstore(storageSlot, 0)
                        }
                    }
                    /**
                     * @dev Private function to clear a TSTORISH value with sstore fallback. 
                     *      Assigned to _clearTstorish internal function variable at construction
                     *      if chain does not have tstore support.
                     *
                     * @param storageSlot The slot to clear the TSTORISH value for.
                     */
                    function _clearTstorishWithSstoreFallback(uint256 storageSlot) private {
                        if (_tstoreSupport) {
                            assembly {
                                tstore(storageSlot, 0)
                            }
                        } else {
                            assembly {
                                sstore(storageSlot, 0)
                            }
                        }
                    }
                    /**
                     * @dev Private function to deploy a test contract that utilizes TLOAD as
                     *      part of its fallback logic.
                     */
                    function _prepareTloadTest() private returns (address contractAddress) {
                        // Utilize assembly to deploy a contract testing TLOAD support.
                        assembly {
                            // Write the contract deployment code payload to scratch space.
                            mstore(0, _TLOAD_TEST_PAYLOAD)
                            // Deploy the contract.
                            contractAddress := create(
                                0,
                                _TLOAD_TEST_PAYLOAD_OFFSET,
                                _TLOAD_TEST_PAYLOAD_LENGTH
                            )
                        }
                    }
                    /**
                     * @dev Private view function to determine if TSTORE/TLOAD are supported by
                     *      the current EVM implementation by attempting to call the test
                     *      contract, which utilizes TLOAD as part of its fallback logic.
                     */
                    function _testTload(
                        address tloadTestContract
                    ) private view returns (bool ok) {
                        // Call the test contract, which will perform a TLOAD test. If the call
                        // does not revert, then TLOAD/TSTORE is supported. Do not forward all
                        // available gas, as all forwarded gas will be consumed on revert.
                        (ok, ) = tloadTestContract.staticcall{ gas: gasleft() / 10 }("");
                    }
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)
                pragma solidity ^0.8.20;
                /**
                 * @dev Interface of the ERC20 standard as defined in the EIP.
                 */
                interface IERC20 {
                    /**
                     * @dev Emitted when `value` tokens are moved from one account (`from`) to
                     * another (`to`).
                     *
                     * Note that `value` may be zero.
                     */
                    event Transfer(address indexed from, address indexed to, uint256 value);
                    /**
                     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                     * a call to {approve}. `value` is the new allowance.
                     */
                    event Approval(address indexed owner, address indexed spender, uint256 value);
                    /**
                     * @dev Returns the value of tokens in existence.
                     */
                    function totalSupply() external view returns (uint256);
                    /**
                     * @dev Returns the value of tokens owned by `account`.
                     */
                    function balanceOf(address account) external view returns (uint256);
                    /**
                     * @dev Moves a `value` amount of tokens from the caller's account to `to`.
                     *
                     * Returns a boolean value indicating whether the operation succeeded.
                     *
                     * Emits a {Transfer} event.
                     */
                    function transfer(address to, uint256 value) external returns (bool);
                    /**
                     * @dev Returns the remaining number of tokens that `spender` will be
                     * allowed to spend on behalf of `owner` through {transferFrom}. This is
                     * zero by default.
                     *
                     * This value changes when {approve} or {transferFrom} are called.
                     */
                    function allowance(address owner, address spender) external view returns (uint256);
                    /**
                     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
                     * caller's tokens.
                     *
                     * Returns a boolean value indicating whether the operation succeeded.
                     *
                     * IMPORTANT: Beware that changing an allowance with this method brings the risk
                     * that someone may use both the old and the new allowance by unfortunate
                     * transaction ordering. One possible solution to mitigate this race
                     * condition is to first reduce the spender's allowance to 0 and set the
                     * desired value afterwards:
                     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                     *
                     * Emits an {Approval} event.
                     */
                    function approve(address spender, uint256 value) external returns (bool);
                    /**
                     * @dev Moves a `value` amount of tokens from `from` to `to` using the
                     * allowance mechanism. `value` is then deducted from the caller's
                     * allowance.
                     *
                     * Returns a boolean value indicating whether the operation succeeded.
                     *
                     * Emits a {Transfer} event.
                     */
                    function transferFrom(address from, address to, uint256 value) external returns (bool);
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/IERC721.sol)
                pragma solidity ^0.8.20;
                import {IERC165} from "../../utils/introspection/IERC165.sol";
                /**
                 * @dev Required interface of an ERC721 compliant contract.
                 */
                interface IERC721 is IERC165 {
                    /**
                     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
                     */
                    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
                    /**
                     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
                     */
                    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
                    /**
                     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
                     */
                    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
                    /**
                     * @dev Returns the number of tokens in ``owner``'s account.
                     */
                    function balanceOf(address owner) external view returns (uint256 balance);
                    /**
                     * @dev Returns the owner of the `tokenId` token.
                     *
                     * Requirements:
                     *
                     * - `tokenId` must exist.
                     */
                    function ownerOf(uint256 tokenId) external view returns (address owner);
                    /**
                     * @dev Safely transfers `tokenId` token from `from` to `to`.
                     *
                     * Requirements:
                     *
                     * - `from` cannot be the zero address.
                     * - `to` cannot be the zero address.
                     * - `tokenId` token must exist and be owned by `from`.
                     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
                     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon
                     *   a safe transfer.
                     *
                     * Emits a {Transfer} event.
                     */
                    function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
                    /**
                     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
                     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
                     *
                     * Requirements:
                     *
                     * - `from` cannot be the zero address.
                     * - `to` cannot be the zero address.
                     * - `tokenId` token must exist and be owned by `from`.
                     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or
                     *   {setApprovalForAll}.
                     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon
                     *   a safe transfer.
                     *
                     * Emits a {Transfer} event.
                     */
                    function safeTransferFrom(address from, address to, uint256 tokenId) external;
                    /**
                     * @dev Transfers `tokenId` token from `from` to `to`.
                     *
                     * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
                     * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
                     * understand this adds an external call which potentially creates a reentrancy vulnerability.
                     *
                     * Requirements:
                     *
                     * - `from` cannot be the zero address.
                     * - `to` cannot be the zero address.
                     * - `tokenId` token must be owned by `from`.
                     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
                     *
                     * Emits a {Transfer} event.
                     */
                    function transferFrom(address from, address to, uint256 tokenId) external;
                    /**
                     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
                     * The approval is cleared when the token is transferred.
                     *
                     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
                     *
                     * Requirements:
                     *
                     * - The caller must own the token or be an approved operator.
                     * - `tokenId` must exist.
                     *
                     * Emits an {Approval} event.
                     */
                    function approve(address to, uint256 tokenId) external;
                    /**
                     * @dev Approve or remove `operator` as an operator for the caller.
                     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
                     *
                     * Requirements:
                     *
                     * - The `operator` cannot be the address zero.
                     *
                     * Emits an {ApprovalForAll} event.
                     */
                    function setApprovalForAll(address operator, bool approved) external;
                    /**
                     * @dev Returns the account approved for `tokenId` token.
                     *
                     * Requirements:
                     *
                     * - `tokenId` must exist.
                     */
                    function getApproved(uint256 tokenId) external view returns (address operator);
                    /**
                     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
                     *
                     * See {setApprovalForAll}
                     */
                    function isApprovedForAll(address owner, address operator) external view returns (bool);
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.1) (token/ERC1155/IERC1155.sol)
                pragma solidity ^0.8.20;
                import {IERC165} from "../../utils/introspection/IERC165.sol";
                /**
                 * @dev Required interface of an ERC1155 compliant contract, as defined in the
                 * https://eips.ethereum.org/EIPS/eip-1155[EIP].
                 */
                interface IERC1155 is IERC165 {
                    /**
                     * @dev Emitted when `value` amount of tokens of type `id` are transferred from `from` to `to` by `operator`.
                     */
                    event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);
                    /**
                     * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
                     * transfers.
                     */
                    event TransferBatch(
                        address indexed operator,
                        address indexed from,
                        address indexed to,
                        uint256[] ids,
                        uint256[] values
                    );
                    /**
                     * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
                     * `approved`.
                     */
                    event ApprovalForAll(address indexed account, address indexed operator, bool approved);
                    /**
                     * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
                     *
                     * If an {URI} event was emitted for `id`, the standard
                     * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
                     * returned by {IERC1155MetadataURI-uri}.
                     */
                    event URI(string value, uint256 indexed id);
                    /**
                     * @dev Returns the value of tokens of token type `id` owned by `account`.
                     *
                     * Requirements:
                     *
                     * - `account` cannot be the zero address.
                     */
                    function balanceOf(address account, uint256 id) external view returns (uint256);
                    /**
                     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
                     *
                     * Requirements:
                     *
                     * - `accounts` and `ids` must have the same length.
                     */
                    function balanceOfBatch(
                        address[] calldata accounts,
                        uint256[] calldata ids
                    ) external view returns (uint256[] memory);
                    /**
                     * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
                     *
                     * Emits an {ApprovalForAll} event.
                     *
                     * Requirements:
                     *
                     * - `operator` cannot be the caller.
                     */
                    function setApprovalForAll(address operator, bool approved) external;
                    /**
                     * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
                     *
                     * See {setApprovalForAll}.
                     */
                    function isApprovedForAll(address account, address operator) external view returns (bool);
                    /**
                     * @dev Transfers a `value` amount of tokens of type `id` from `from` to `to`.
                     *
                     * WARNING: This function can potentially allow a reentrancy attack when transferring tokens
                     * to an untrusted contract, when invoking {onERC1155Received} on the receiver.
                     * Ensure to follow the checks-effects-interactions pattern and consider employing
                     * reentrancy guards when interacting with untrusted contracts.
                     *
                     * Emits a {TransferSingle} event.
                     *
                     * Requirements:
                     *
                     * - `to` cannot be the zero address.
                     * - If the caller is not `from`, it must have been approved to spend ``from``'s tokens via {setApprovalForAll}.
                     * - `from` must have a balance of tokens of type `id` of at least `value` amount.
                     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
                     * acceptance magic value.
                     */
                    function safeTransferFrom(address from, address to, uint256 id, uint256 value, bytes calldata data) external;
                    /**
                     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
                     *
                     * WARNING: This function can potentially allow a reentrancy attack when transferring tokens
                     * to an untrusted contract, when invoking {onERC1155BatchReceived} on the receiver.
                     * Ensure to follow the checks-effects-interactions pattern and consider employing
                     * reentrancy guards when interacting with untrusted contracts.
                     *
                     * Emits either a {TransferSingle} or a {TransferBatch} event, depending on the length of the array arguments.
                     *
                     * Requirements:
                     *
                     * - `ids` and `values` must have the same length.
                     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
                     * acceptance magic value.
                     */
                    function safeBatchTransferFrom(
                        address from,
                        address to,
                        uint256[] calldata ids,
                        uint256[] calldata values,
                        bytes calldata data
                    ) external;
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)
                pragma solidity ^0.8.20;
                import {IERC20} from "../IERC20.sol";
                import {IERC20Permit} from "../extensions/IERC20Permit.sol";
                import {Address} from "../../../utils/Address.sol";
                /**
                 * @title SafeERC20
                 * @dev Wrappers around ERC20 operations that throw on failure (when the token
                 * contract returns false). Tokens that return no value (and instead revert or
                 * throw on failure) are also supported, non-reverting calls are assumed to be
                 * successful.
                 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
                 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
                 */
                library SafeERC20 {
                    using Address for address;
                    /**
                     * @dev An operation with an ERC20 token failed.
                     */
                    error SafeERC20FailedOperation(address token);
                    /**
                     * @dev Indicates a failed `decreaseAllowance` request.
                     */
                    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);
                    /**
                     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
                     * non-reverting calls are assumed to be successful.
                     */
                    function safeTransfer(IERC20 token, address to, uint256 value) internal {
                        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
                    }
                    /**
                     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
                     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
                     */
                    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
                        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
                    }
                    /**
                     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
                     * non-reverting calls are assumed to be successful.
                     */
                    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                        uint256 oldAllowance = token.allowance(address(this), spender);
                        forceApprove(token, spender, oldAllowance + value);
                    }
                    /**
                     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
                     * value, non-reverting calls are assumed to be successful.
                     */
                    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
                        unchecked {
                            uint256 currentAllowance = token.allowance(address(this), spender);
                            if (currentAllowance < requestedDecrease) {
                                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
                            }
                            forceApprove(token, spender, currentAllowance - requestedDecrease);
                        }
                    }
                    /**
                     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
                     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
                     * to be set to zero before setting it to a non-zero value, such as USDT.
                     */
                    function forceApprove(IERC20 token, address spender, uint256 value) internal {
                        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));
                        if (!_callOptionalReturnBool(token, approvalCall)) {
                            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
                            _callOptionalReturn(token, approvalCall);
                        }
                    }
                    /**
                     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                     * on the return value: the return value is optional (but if data is returned, it must not be false).
                     * @param token The token targeted by the call.
                     * @param data The call data (encoded using abi.encode or one of its variants).
                     */
                    function _callOptionalReturn(IERC20 token, bytes memory data) private {
                        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
                        // the target address contains contract code and also asserts for success in the low-level call.
                        bytes memory returndata = address(token).functionCall(data);
                        if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
                            revert SafeERC20FailedOperation(address(token));
                        }
                    }
                    /**
                     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                     * on the return value: the return value is optional (but if data is returned, it must not be false).
                     * @param token The token targeted by the call.
                     * @param data The call data (encoded using abi.encode or one of its variants).
                     *
                     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
                     */
                    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
                        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
                        // and not revert is the subcall reverts.
                        (bool success, bytes memory returndata) = address(token).call(data);
                        return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                import {IEIP712} from "./IEIP712.sol";
                /// @title AllowanceTransfer
                /// @notice Handles ERC20 token permissions through signature based allowance setting and ERC20 token transfers by checking allowed amounts
                /// @dev Requires user's token approval on the Permit2 contract
                interface IAllowanceTransfer is IEIP712 {
                    /// @notice Thrown when an allowance on a token has expired.
                    /// @param deadline The timestamp at which the allowed amount is no longer valid
                    error AllowanceExpired(uint256 deadline);
                    /// @notice Thrown when an allowance on a token has been depleted.
                    /// @param amount The maximum amount allowed
                    error InsufficientAllowance(uint256 amount);
                    /// @notice Thrown when too many nonces are invalidated.
                    error ExcessiveInvalidation();
                    /// @notice Emits an event when the owner successfully invalidates an ordered nonce.
                    event NonceInvalidation(
                        address indexed owner, address indexed token, address indexed spender, uint48 newNonce, uint48 oldNonce
                    );
                    /// @notice Emits an event when the owner successfully sets permissions on a token for the spender.
                    event Approval(
                        address indexed owner, address indexed token, address indexed spender, uint160 amount, uint48 expiration
                    );
                    /// @notice Emits an event when the owner successfully sets permissions using a permit signature on a token for the spender.
                    event Permit(
                        address indexed owner,
                        address indexed token,
                        address indexed spender,
                        uint160 amount,
                        uint48 expiration,
                        uint48 nonce
                    );
                    /// @notice Emits an event when the owner sets the allowance back to 0 with the lockdown function.
                    event Lockdown(address indexed owner, address token, address spender);
                    /// @notice The permit data for a token
                    struct PermitDetails {
                        // ERC20 token address
                        address token;
                        // the maximum amount allowed to spend
                        uint160 amount;
                        // timestamp at which a spender's token allowances become invalid
                        uint48 expiration;
                        // an incrementing value indexed per owner,token,and spender for each signature
                        uint48 nonce;
                    }
                    /// @notice The permit message signed for a single token allowance
                    struct PermitSingle {
                        // the permit data for a single token alownce
                        PermitDetails details;
                        // address permissioned on the allowed tokens
                        address spender;
                        // deadline on the permit signature
                        uint256 sigDeadline;
                    }
                    /// @notice The permit message signed for multiple token allowances
                    struct PermitBatch {
                        // the permit data for multiple token allowances
                        PermitDetails[] details;
                        // address permissioned on the allowed tokens
                        address spender;
                        // deadline on the permit signature
                        uint256 sigDeadline;
                    }
                    /// @notice The saved permissions
                    /// @dev This info is saved per owner, per token, per spender and all signed over in the permit message
                    /// @dev Setting amount to type(uint160).max sets an unlimited approval
                    struct PackedAllowance {
                        // amount allowed
                        uint160 amount;
                        // permission expiry
                        uint48 expiration;
                        // an incrementing value indexed per owner,token,and spender for each signature
                        uint48 nonce;
                    }
                    /// @notice A token spender pair.
                    struct TokenSpenderPair {
                        // the token the spender is approved
                        address token;
                        // the spender address
                        address spender;
                    }
                    /// @notice Details for a token transfer.
                    struct AllowanceTransferDetails {
                        // the owner of the token
                        address from;
                        // the recipient of the token
                        address to;
                        // the amount of the token
                        uint160 amount;
                        // the token to be transferred
                        address token;
                    }
                    /// @notice A mapping from owner address to token address to spender address to PackedAllowance struct, which contains details and conditions of the approval.
                    /// @notice The mapping is indexed in the above order see: allowance[ownerAddress][tokenAddress][spenderAddress]
                    /// @dev The packed slot holds the allowed amount, expiration at which the allowed amount is no longer valid, and current nonce thats updated on any signature based approvals.
                    function allowance(address user, address token, address spender)
                        external
                        view
                        returns (uint160 amount, uint48 expiration, uint48 nonce);
                    /// @notice Approves the spender to use up to amount of the specified token up until the expiration
                    /// @param token The token to approve
                    /// @param spender The spender address to approve
                    /// @param amount The approved amount of the token
                    /// @param expiration The timestamp at which the approval is no longer valid
                    /// @dev The packed allowance also holds a nonce, which will stay unchanged in approve
                    /// @dev Setting amount to type(uint160).max sets an unlimited approval
                    function approve(address token, address spender, uint160 amount, uint48 expiration) external;
                    /// @notice Permit a spender to a given amount of the owners token via the owner's EIP-712 signature
                    /// @dev May fail if the owner's nonce was invalidated in-flight by invalidateNonce
                    /// @param owner The owner of the tokens being approved
                    /// @param permitSingle Data signed over by the owner specifying the terms of approval
                    /// @param signature The owner's signature over the permit data
                    function permit(address owner, PermitSingle memory permitSingle, bytes calldata signature) external;
                    /// @notice Permit a spender to the signed amounts of the owners tokens via the owner's EIP-712 signature
                    /// @dev May fail if the owner's nonce was invalidated in-flight by invalidateNonce
                    /// @param owner The owner of the tokens being approved
                    /// @param permitBatch Data signed over by the owner specifying the terms of approval
                    /// @param signature The owner's signature over the permit data
                    function permit(address owner, PermitBatch memory permitBatch, bytes calldata signature) external;
                    /// @notice Transfer approved tokens from one address to another
                    /// @param from The address to transfer from
                    /// @param to The address of the recipient
                    /// @param amount The amount of the token to transfer
                    /// @param token The token address to transfer
                    /// @dev Requires the from address to have approved at least the desired amount
                    /// of tokens to msg.sender.
                    function transferFrom(address from, address to, uint160 amount, address token) external;
                    /// @notice Transfer approved tokens in a batch
                    /// @param transferDetails Array of owners, recipients, amounts, and tokens for the transfers
                    /// @dev Requires the from addresses to have approved at least the desired amount
                    /// of tokens to msg.sender.
                    function transferFrom(AllowanceTransferDetails[] calldata transferDetails) external;
                    /// @notice Enables performing a "lockdown" of the sender's Permit2 identity
                    /// by batch revoking approvals
                    /// @param approvals Array of approvals to revoke.
                    function lockdown(TokenSpenderPair[] calldata approvals) external;
                    /// @notice Invalidate nonces for a given (token, spender) pair
                    /// @param token The token to invalidate nonces for
                    /// @param spender The spender to invalidate nonces for
                    /// @param newNonce The new nonce to set. Invalidates all nonces less than it.
                    /// @dev Can't invalidate more than 2**16 nonces per transaction.
                    function invalidateNonces(address token, address spender, uint48 newNonce) external;
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                import {IEIP712} from "./IEIP712.sol";
                /// @title SignatureTransfer
                /// @notice Handles ERC20 token transfers through signature based actions
                /// @dev Requires user's token approval on the Permit2 contract
                interface ISignatureTransfer is IEIP712 {
                    /// @notice Thrown when the requested amount for a transfer is larger than the permissioned amount
                    /// @param maxAmount The maximum amount a spender can request to transfer
                    error InvalidAmount(uint256 maxAmount);
                    /// @notice Thrown when the number of tokens permissioned to a spender does not match the number of tokens being transferred
                    /// @dev If the spender does not need to transfer the number of tokens permitted, the spender can request amount 0 to be transferred
                    error LengthMismatch();
                    /// @notice Emits an event when the owner successfully invalidates an unordered nonce.
                    event UnorderedNonceInvalidation(address indexed owner, uint256 word, uint256 mask);
                    /// @notice The token and amount details for a transfer signed in the permit transfer signature
                    struct TokenPermissions {
                        // ERC20 token address
                        address token;
                        // the maximum amount that can be spent
                        uint256 amount;
                    }
                    /// @notice The signed permit message for a single token transfer
                    struct PermitTransferFrom {
                        TokenPermissions permitted;
                        // a unique value for every token owner's signature to prevent signature replays
                        uint256 nonce;
                        // deadline on the permit signature
                        uint256 deadline;
                    }
                    /// @notice Specifies the recipient address and amount for batched transfers.
                    /// @dev Recipients and amounts correspond to the index of the signed token permissions array.
                    /// @dev Reverts if the requested amount is greater than the permitted signed amount.
                    struct SignatureTransferDetails {
                        // recipient address
                        address to;
                        // spender requested amount
                        uint256 requestedAmount;
                    }
                    /// @notice Used to reconstruct the signed permit message for multiple token transfers
                    /// @dev Do not need to pass in spender address as it is required that it is msg.sender
                    /// @dev Note that a user still signs over a spender address
                    struct PermitBatchTransferFrom {
                        // the tokens and corresponding amounts permitted for a transfer
                        TokenPermissions[] permitted;
                        // a unique value for every token owner's signature to prevent signature replays
                        uint256 nonce;
                        // deadline on the permit signature
                        uint256 deadline;
                    }
                    /// @notice A map from token owner address and a caller specified word index to a bitmap. Used to set bits in the bitmap to prevent against signature replay protection
                    /// @dev Uses unordered nonces so that permit messages do not need to be spent in a certain order
                    /// @dev The mapping is indexed first by the token owner, then by an index specified in the nonce
                    /// @dev It returns a uint256 bitmap
                    /// @dev The index, or wordPosition is capped at type(uint248).max
                    function nonceBitmap(address, uint256) external view returns (uint256);
                    /// @notice Transfers a token using a signed permit message
                    /// @dev Reverts if the requested amount is greater than the permitted signed amount
                    /// @param permit The permit data signed over by the owner
                    /// @param owner The owner of the tokens to transfer
                    /// @param transferDetails The spender's requested transfer details for the permitted token
                    /// @param signature The signature to verify
                    function permitTransferFrom(
                        PermitTransferFrom memory permit,
                        SignatureTransferDetails calldata transferDetails,
                        address owner,
                        bytes calldata signature
                    ) external;
                    /// @notice Transfers a token using a signed permit message
                    /// @notice Includes extra data provided by the caller to verify signature over
                    /// @dev The witness type string must follow EIP712 ordering of nested structs and must include the TokenPermissions type definition
                    /// @dev Reverts if the requested amount is greater than the permitted signed amount
                    /// @param permit The permit data signed over by the owner
                    /// @param owner The owner of the tokens to transfer
                    /// @param transferDetails The spender's requested transfer details for the permitted token
                    /// @param witness Extra data to include when checking the user signature
                    /// @param witnessTypeString The EIP-712 type definition for remaining string stub of the typehash
                    /// @param signature The signature to verify
                    function permitWitnessTransferFrom(
                        PermitTransferFrom memory permit,
                        SignatureTransferDetails calldata transferDetails,
                        address owner,
                        bytes32 witness,
                        string calldata witnessTypeString,
                        bytes calldata signature
                    ) external;
                    /// @notice Transfers multiple tokens using a signed permit message
                    /// @param permit The permit data signed over by the owner
                    /// @param owner The owner of the tokens to transfer
                    /// @param transferDetails Specifies the recipient and requested amount for the token transfer
                    /// @param signature The signature to verify
                    function permitTransferFrom(
                        PermitBatchTransferFrom memory permit,
                        SignatureTransferDetails[] calldata transferDetails,
                        address owner,
                        bytes calldata signature
                    ) external;
                    /// @notice Transfers multiple tokens using a signed permit message
                    /// @dev The witness type string must follow EIP712 ordering of nested structs and must include the TokenPermissions type definition
                    /// @notice Includes extra data provided by the caller to verify signature over
                    /// @param permit The permit data signed over by the owner
                    /// @param owner The owner of the tokens to transfer
                    /// @param transferDetails Specifies the recipient and requested amount for the token transfer
                    /// @param witness Extra data to include when checking the user signature
                    /// @param witnessTypeString The EIP-712 type definition for remaining string stub of the typehash
                    /// @param signature The signature to verify
                    function permitWitnessTransferFrom(
                        PermitBatchTransferFrom memory permit,
                        SignatureTransferDetails[] calldata transferDetails,
                        address owner,
                        bytes32 witness,
                        string calldata witnessTypeString,
                        bytes calldata signature
                    ) external;
                    /// @notice Invalidates the bits specified in mask for the bitmap at the word position
                    /// @dev The wordPos is maxed at type(uint248).max
                    /// @param wordPos A number to index the nonceBitmap at
                    /// @param mask A bitmap masked against msg.sender's current bitmap at the word position
                    function invalidateUnorderedNonces(uint256 wordPos, uint256 mask) external;
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                import {ISignatureTransfer} from "./ISignatureTransfer.sol";
                import {IAllowanceTransfer} from "./IAllowanceTransfer.sol";
                /// @notice Permit2 handles signature-based transfers in SignatureTransfer and allowance-based transfers in AllowanceTransfer.
                /// @dev Users must approve Permit2 before calling any of the transfer functions.
                interface IPermit2 is ISignatureTransfer, IAllowanceTransfer {
                // IPermit2 unifies the two interfaces so users have maximal flexibility with their approval.
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.23;
                enum OrderStatus {
                    NotInitiated,
                    Initiated,
                    Settled__FulfilledPrimary,
                    Settled__FulfilledSecondary,
                    Settled__Refund,
                    Cancelled
                }
                enum Verdict {
                    FulfilledPrimary,
                    FulfilledSecondary,
                    Refund
                }
                /// @notice A struct representing an input or output token transfer. These transfers must take place
                ///         on their respective chains in order for validators to sign the order.
                /// @param token   The address of the token to transfer
                /// @param from    The from address
                /// @param to      The to address
                /// @param amount  The amount to transfer
                /// @param chainId The chainId of the transfer
                struct TokenTransfer {
                    address token; // address(0) for native, erc20 otherwise
                    address from;
                    address to;
                    uint256 amount;
                    uint256 chainId; // chainId of 0 means escrow balance should be transferred between `from` and `to`
                }
                /// @notice A call to be executed as part of the order. If a call is representing a "pre-hook", the output
                ///         of the call will be bridged to the destination chain. If a call is representing a "post-hook",
                ///         the output of the call will be sent to the user.
                /// @param to        The address of the contract to call
                /// @param isPreHook If true, the call is a "pre-hook". If false, the call is a "post-hook"
                /// @param value     The value to send with the call
                /// @param data      The data to send with the call
                struct Route {
                    address to;
                    uint256 value;
                    uint256 chainId;
                    bytes data;
                }
                /// @notice An order that can be sequenced and settled by the protocol
                ///         To complete the order lifecycle, the order must be signed by the user, relayer, validator, and oracle
                /// @param user             The address of the user
                /// @param relayer          The address of the relayer
                /// @param validator        The address of the validator
                /// @param collateralAmount The amount of collateral to lock as part of the order
                /// @param expiration       The order expiration timestamp. If a validator determines that input tokens haven't been transferred by expiration,
                ///                         it can cancel the order.
                /// @param intentCommit     A hash of the order's input and output TokenTransfer[], or the order's "intent". Any internal Relay ETH fees to other
                ///                         parties in the order lifecylce should be specified in the output array. Note that the order of the encoded inputs will affect
                ///                         the intentCommit hash. The intentCommit is meant to be revealed in the call to `settleOrder`.
                /// @param primaryCommit    A hash of the order's origin and destination Route[]. This route should satisfy the hashed intentCommit.
                ///                         The routeCommit is meant to be verified offchain between the relayer and the validator.
                /// @param hookCommit       A hash of the order's pre and post hooks, if necessary. Note that the pre hook will be executed with the user's input tokens
                ///                         on the origin chain, and the post hook will be executed with the user's output tokens on the destination chain
                struct Order {
                    address user;
                    address relayer;
                    address validator;
                    uint256 nonce;
                    uint256 collateralAmount;
                    uint256 inputDeadline;
                    uint256 primaryDeadline;
                    uint256 secondaryDeadline;
                    bytes32 intentCommit;
                    bytes32 primaryCommit;
                    bytes32 secondaryCommit;
                }
                /// @notice Collateral balances (user or relayer)
                /// @param totalBalance The total balance of the account
                /// @param outstandingBalance The balance locked in initiated but unsettled orders
                /// @param relayEthBalance Surplus ETH from fees that can be used to pay for fees or gas
                struct Balances {
                    uint256 totalBalance;
                    uint256 outstandingBalance;
                    uint256 relayEthBalance;
                }
                struct RelayerWitness {
                    address relayer;
                }
                struct EscrowBalance {
                    uint256 timelock;
                    uint256 lockedBalance;
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.4;
                /**
                 * @title IMulticaller
                 * @notice Interface for the Multicaller contract.
                 */
                interface IMulticaller {
                    /**
                     * @dev Aggregates multiple calls in a single transaction.
                     * @param targets  An array of addresses to call.
                     * @param data     An array of calldata to forward to the targets.
                     * @param values   How much ETH to forward to each target.
                     * @param refundTo The address to transfer any remaining ETH in the contract after the calls.
                     *                 If `address(0)`, remaining ETH will NOT be refunded.
                     *                 If `address(1)`, remaining ETH will be refunded to `msg.sender`.
                     *                 If anything else, remaining ETH will be refunded to `refundTo`.
                     * @return An array of the returndata from each call.
                     */
                    function aggregate(
                        address[] calldata targets,
                        bytes[] calldata data,
                        uint256[] calldata values,
                        address refundTo
                    ) external payable returns (bytes[] memory);
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/IERC165.sol)
                pragma solidity ^0.8.20;
                /**
                 * @dev Interface of the ERC165 standard, as defined in the
                 * https://eips.ethereum.org/EIPS/eip-165[EIP].
                 *
                 * Implementers can declare support of contract interfaces, which can then be
                 * queried by others ({ERC165Checker}).
                 *
                 * For an implementation, see {ERC165}.
                 */
                interface IERC165 {
                    /**
                     * @dev Returns true if this contract implements the interface defined by
                     * `interfaceId`. See the corresponding
                     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                     * to learn more about how these ids are created.
                     *
                     * This function call must use less than 30 000 gas.
                     */
                    function supportsInterface(bytes4 interfaceId) external view returns (bool);
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)
                pragma solidity ^0.8.20;
                /**
                 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
                 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
                 *
                 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
                 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
                 * need to send a transaction, and thus is not required to hold Ether at all.
                 *
                 * ==== Security Considerations
                 *
                 * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
                 * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
                 * considered as an intention to spend the allowance in any specific way. The second is that because permits have
                 * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
                 * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
                 * generally recommended is:
                 *
                 * ```solidity
                 * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
                 *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
                 *     doThing(..., value);
                 * }
                 *
                 * function doThing(..., uint256 value) public {
                 *     token.safeTransferFrom(msg.sender, address(this), value);
                 *     ...
                 * }
                 * ```
                 *
                 * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
                 * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
                 * {SafeERC20-safeTransferFrom}).
                 *
                 * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
                 * contracts should have entry points that don't rely on permit.
                 */
                interface IERC20Permit {
                    /**
                     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
                     * given ``owner``'s signed approval.
                     *
                     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
                     * ordering also apply here.
                     *
                     * Emits an {Approval} event.
                     *
                     * Requirements:
                     *
                     * - `spender` cannot be the zero address.
                     * - `deadline` must be a timestamp in the future.
                     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
                     * over the EIP712-formatted function arguments.
                     * - the signature must use ``owner``'s current nonce (see {nonces}).
                     *
                     * For more information on the signature format, see the
                     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
                     * section].
                     *
                     * CAUTION: See Security Considerations above.
                     */
                    function permit(
                        address owner,
                        address spender,
                        uint256 value,
                        uint256 deadline,
                        uint8 v,
                        bytes32 r,
                        bytes32 s
                    ) external;
                    /**
                     * @dev Returns the current nonce for `owner`. This value must be
                     * included whenever a signature is generated for {permit}.
                     *
                     * Every successful call to {permit} increases ``owner``'s nonce by one. This
                     * prevents a signature from being used multiple times.
                     */
                    function nonces(address owner) external view returns (uint256);
                    /**
                     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
                     */
                    // solhint-disable-next-line func-name-mixedcase
                    function DOMAIN_SEPARATOR() external view returns (bytes32);
                }
                // SPDX-License-Identifier: MIT
                // OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)
                pragma solidity ^0.8.20;
                /**
                 * @dev Collection of functions related to the address type
                 */
                library Address {
                    /**
                     * @dev The ETH balance of the account is not enough to perform the operation.
                     */
                    error AddressInsufficientBalance(address account);
                    /**
                     * @dev There's no code at `target` (it is not a contract).
                     */
                    error AddressEmptyCode(address target);
                    /**
                     * @dev A call to an address target failed. The target may have reverted.
                     */
                    error FailedInnerCall();
                    /**
                     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                     * `recipient`, forwarding all available gas and reverting on errors.
                     *
                     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                     * of certain opcodes, possibly making contracts go over the 2300 gas limit
                     * imposed by `transfer`, making them unable to receive funds via
                     * `transfer`. {sendValue} removes this limitation.
                     *
                     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                     *
                     * IMPORTANT: because control is transferred to `recipient`, care must be
                     * taken to not create reentrancy vulnerabilities. Consider using
                     * {ReentrancyGuard} or the
                     * https://solidity.readthedocs.io/en/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                     */
                    function sendValue(address payable recipient, uint256 amount) internal {
                        if (address(this).balance < amount) {
                            revert AddressInsufficientBalance(address(this));
                        }
                        (bool success, ) = recipient.call{value: amount}("");
                        if (!success) {
                            revert FailedInnerCall();
                        }
                    }
                    /**
                     * @dev Performs a Solidity function call using a low level `call`. A
                     * plain `call` is an unsafe replacement for a function call: use this
                     * function instead.
                     *
                     * If `target` reverts with a revert reason or custom error, it is bubbled
                     * up by this function (like regular Solidity function calls). However, if
                     * the call reverted with no returned reason, this function reverts with a
                     * {FailedInnerCall} error.
                     *
                     * Returns the raw returned data. To convert to the expected return value,
                     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                     *
                     * Requirements:
                     *
                     * - `target` must be a contract.
                     * - calling `target` with `data` must not revert.
                     */
                    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                        return functionCallWithValue(target, data, 0);
                    }
                    /**
                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                     * but also transferring `value` wei to `target`.
                     *
                     * Requirements:
                     *
                     * - the calling contract must have an ETH balance of at least `value`.
                     * - the called Solidity function must be `payable`.
                     */
                    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                        if (address(this).balance < value) {
                            revert AddressInsufficientBalance(address(this));
                        }
                        (bool success, bytes memory returndata) = target.call{value: value}(data);
                        return verifyCallResultFromTarget(target, success, returndata);
                    }
                    /**
                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                     * but performing a static call.
                     */
                    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                        (bool success, bytes memory returndata) = target.staticcall(data);
                        return verifyCallResultFromTarget(target, success, returndata);
                    }
                    /**
                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                     * but performing a delegate call.
                     */
                    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                        (bool success, bytes memory returndata) = target.delegatecall(data);
                        return verifyCallResultFromTarget(target, success, returndata);
                    }
                    /**
                     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
                     * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
                     * unsuccessful call.
                     */
                    function verifyCallResultFromTarget(
                        address target,
                        bool success,
                        bytes memory returndata
                    ) internal view returns (bytes memory) {
                        if (!success) {
                            _revert(returndata);
                        } else {
                            // only check if target is a contract if the call was successful and the return data is empty
                            // otherwise we already know that it was a contract
                            if (returndata.length == 0 && target.code.length == 0) {
                                revert AddressEmptyCode(target);
                            }
                            return returndata;
                        }
                    }
                    /**
                     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
                     * revert reason or with a default {FailedInnerCall} error.
                     */
                    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
                        if (!success) {
                            _revert(returndata);
                        } else {
                            return returndata;
                        }
                    }
                    /**
                     * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
                     */
                    function _revert(bytes memory returndata) private pure {
                        // Look for revert reason and bubble it up if present
                        if (returndata.length > 0) {
                            // The easiest way to bubble the revert reason is using memory via assembly
                            /// @solidity memory-safe-assembly
                            assembly {
                                let returndata_size := mload(returndata)
                                revert(add(32, returndata), returndata_size)
                            }
                        } else {
                            revert FailedInnerCall();
                        }
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                interface IEIP712 {
                    function DOMAIN_SEPARATOR() external view returns (bytes32);
                }
                

                File 3 of 7: BNB
                pragma solidity ^0.4.8;
                
                /**
                 * Math operations with safety checks
                 */
                contract SafeMath {
                  function safeMul(uint256 a, uint256 b) internal returns (uint256) {
                    uint256 c = a * b;
                    assert(a == 0 || c / a == b);
                    return c;
                  }
                
                  function safeDiv(uint256 a, uint256 b) internal returns (uint256) {
                    assert(b > 0);
                    uint256 c = a / b;
                    assert(a == b * c + a % b);
                    return c;
                  }
                
                  function safeSub(uint256 a, uint256 b) internal returns (uint256) {
                    assert(b <= a);
                    return a - b;
                  }
                
                  function safeAdd(uint256 a, uint256 b) internal returns (uint256) {
                    uint256 c = a + b;
                    assert(c>=a && c>=b);
                    return c;
                  }
                
                  function assert(bool assertion) internal {
                    if (!assertion) {
                      throw;
                    }
                  }
                }
                contract BNB is SafeMath{
                    string public name;
                    string public symbol;
                    uint8 public decimals;
                    uint256 public totalSupply;
                	address public owner;
                
                    /* This creates an array with all balances */
                    mapping (address => uint256) public balanceOf;
                	mapping (address => uint256) public freezeOf;
                    mapping (address => mapping (address => uint256)) public allowance;
                
                    /* This generates a public event on the blockchain that will notify clients */
                    event Transfer(address indexed from, address indexed to, uint256 value);
                
                    /* This notifies clients about the amount burnt */
                    event Burn(address indexed from, uint256 value);
                	
                	/* This notifies clients about the amount frozen */
                    event Freeze(address indexed from, uint256 value);
                	
                	/* This notifies clients about the amount unfrozen */
                    event Unfreeze(address indexed from, uint256 value);
                
                    /* Initializes contract with initial supply tokens to the creator of the contract */
                    function BNB(
                        uint256 initialSupply,
                        string tokenName,
                        uint8 decimalUnits,
                        string tokenSymbol
                        ) {
                        balanceOf[msg.sender] = initialSupply;              // Give the creator all initial tokens
                        totalSupply = initialSupply;                        // Update total supply
                        name = tokenName;                                   // Set the name for display purposes
                        symbol = tokenSymbol;                               // Set the symbol for display purposes
                        decimals = decimalUnits;                            // Amount of decimals for display purposes
                		owner = msg.sender;
                    }
                
                    /* Send coins */
                    function transfer(address _to, uint256 _value) {
                        if (_to == 0x0) throw;                               // Prevent transfer to 0x0 address. Use burn() instead
                		if (_value <= 0) throw; 
                        if (balanceOf[msg.sender] < _value) throw;           // Check if the sender has enough
                        if (balanceOf[_to] + _value < balanceOf[_to]) throw; // Check for overflows
                        balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[msg.sender], _value);                     // Subtract from the sender
                        balanceOf[_to] = SafeMath.safeAdd(balanceOf[_to], _value);                            // Add the same to the recipient
                        Transfer(msg.sender, _to, _value);                   // Notify anyone listening that this transfer took place
                    }
                
                    /* Allow another contract to spend some tokens in your behalf */
                    function approve(address _spender, uint256 _value)
                        returns (bool success) {
                		if (_value <= 0) throw; 
                        allowance[msg.sender][_spender] = _value;
                        return true;
                    }
                       
                
                    /* A contract attempts to get the coins */
                    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
                        if (_to == 0x0) throw;                                // Prevent transfer to 0x0 address. Use burn() instead
                		if (_value <= 0) throw; 
                        if (balanceOf[_from] < _value) throw;                 // Check if the sender has enough
                        if (balanceOf[_to] + _value < balanceOf[_to]) throw;  // Check for overflows
                        if (_value > allowance[_from][msg.sender]) throw;     // Check allowance
                        balanceOf[_from] = SafeMath.safeSub(balanceOf[_from], _value);                           // Subtract from the sender
                        balanceOf[_to] = SafeMath.safeAdd(balanceOf[_to], _value);                             // Add the same to the recipient
                        allowance[_from][msg.sender] = SafeMath.safeSub(allowance[_from][msg.sender], _value);
                        Transfer(_from, _to, _value);
                        return true;
                    }
                
                    function burn(uint256 _value) returns (bool success) {
                        if (balanceOf[msg.sender] < _value) throw;            // Check if the sender has enough
                		if (_value <= 0) throw; 
                        balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[msg.sender], _value);                      // Subtract from the sender
                        totalSupply = SafeMath.safeSub(totalSupply,_value);                                // Updates totalSupply
                        Burn(msg.sender, _value);
                        return true;
                    }
                	
                	function freeze(uint256 _value) returns (bool success) {
                        if (balanceOf[msg.sender] < _value) throw;            // Check if the sender has enough
                		if (_value <= 0) throw; 
                        balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[msg.sender], _value);                      // Subtract from the sender
                        freezeOf[msg.sender] = SafeMath.safeAdd(freezeOf[msg.sender], _value);                                // Updates totalSupply
                        Freeze(msg.sender, _value);
                        return true;
                    }
                	
                	function unfreeze(uint256 _value) returns (bool success) {
                        if (freezeOf[msg.sender] < _value) throw;            // Check if the sender has enough
                		if (_value <= 0) throw; 
                        freezeOf[msg.sender] = SafeMath.safeSub(freezeOf[msg.sender], _value);                      // Subtract from the sender
                		balanceOf[msg.sender] = SafeMath.safeAdd(balanceOf[msg.sender], _value);
                        Unfreeze(msg.sender, _value);
                        return true;
                    }
                	
                	// transfer balance to owner
                	function withdrawEther(uint256 amount) {
                		if(msg.sender != owner)throw;
                		owner.transfer(amount);
                	}
                	
                	// can accept ether
                	function() payable {
                    }
                }

                File 4 of 7: ZeroEx
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
                import "./migrations/LibBootstrap.sol";
                import "./features/Bootstrap.sol";
                import "./storage/LibProxyStorage.sol";
                import "./errors/LibProxyRichErrors.sol";
                /// @dev An extensible proxy contract that serves as a universal entry point for
                ///      interacting with the 0x protocol.
                contract ZeroEx {
                    // solhint-disable separate-by-one-line-in-contract,indent,var-name-mixedcase
                    using LibBytesV06 for bytes;
                    /// @dev Construct this contract and register the `Bootstrap` feature.
                    ///      After constructing this contract, `bootstrap()` should be called
                    ///      to seed the initial feature set.
                    constructor() public {
                        // Temporarily create and register the bootstrap feature.
                        // It will deregister itself after `bootstrap()` has been called.
                        Bootstrap bootstrap = new Bootstrap(msg.sender);
                        LibProxyStorage.getStorage().impls[bootstrap.bootstrap.selector] =
                            address(bootstrap);
                    }
                    // solhint-disable state-visibility
                    /// @dev Forwards calls to the appropriate implementation contract.
                    fallback() external payable {
                        bytes4 selector = msg.data.readBytes4(0);
                        address impl = getFunctionImplementation(selector);
                        if (impl == address(0)) {
                            _revertWithData(LibProxyRichErrors.NotImplementedError(selector));
                        }
                        (bool success, bytes memory resultData) = impl.delegatecall(msg.data);
                        if (!success) {
                            _revertWithData(resultData);
                        }
                        _returnWithData(resultData);
                    }
                    /// @dev Fallback for just receiving ether.
                    receive() external payable {}
                    // solhint-enable state-visibility
                    /// @dev Get the implementation contract of a registered function.
                    /// @param selector The function selector.
                    /// @return impl The implementation contract address.
                    function getFunctionImplementation(bytes4 selector)
                        public
                        view
                        returns (address impl)
                    {
                        return LibProxyStorage.getStorage().impls[selector];
                    }
                    /// @dev Revert with arbitrary bytes.
                    /// @param data Revert data.
                    function _revertWithData(bytes memory data) private pure {
                        assembly { revert(add(data, 32), mload(data)) }
                    }
                    /// @dev Return with arbitrary bytes.
                    /// @param data Return data.
                    function _returnWithData(bytes memory data) private pure {
                        assembly { return(add(data, 32), mload(data)) }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "./errors/LibBytesRichErrorsV06.sol";
                import "./errors/LibRichErrorsV06.sol";
                library LibBytesV06 {
                    using LibBytesV06 for bytes;
                    /// @dev Gets the memory address for a byte array.
                    /// @param input Byte array to lookup.
                    /// @return memoryAddress Memory address of byte array. This
                    ///         points to the header of the byte array which contains
                    ///         the length.
                    function rawAddress(bytes memory input)
                        internal
                        pure
                        returns (uint256 memoryAddress)
                    {
                        assembly {
                            memoryAddress := input
                        }
                        return memoryAddress;
                    }
                    /// @dev Gets the memory address for the contents of a byte array.
                    /// @param input Byte array to lookup.
                    /// @return memoryAddress Memory address of the contents of the byte array.
                    function contentAddress(bytes memory input)
                        internal
                        pure
                        returns (uint256 memoryAddress)
                    {
                        assembly {
                            memoryAddress := add(input, 32)
                        }
                        return memoryAddress;
                    }
                    /// @dev Copies `length` bytes from memory location `source` to `dest`.
                    /// @param dest memory address to copy bytes to.
                    /// @param source memory address to copy bytes from.
                    /// @param length number of bytes to copy.
                    function memCopy(
                        uint256 dest,
                        uint256 source,
                        uint256 length
                    )
                        internal
                        pure
                    {
                        if (length < 32) {
                            // Handle a partial word by reading destination and masking
                            // off the bits we are interested in.
                            // This correctly handles overlap, zero lengths and source == dest
                            assembly {
                                let mask := sub(exp(256, sub(32, length)), 1)
                                let s := and(mload(source), not(mask))
                                let d := and(mload(dest), mask)
                                mstore(dest, or(s, d))
                            }
                        } else {
                            // Skip the O(length) loop when source == dest.
                            if (source == dest) {
                                return;
                            }
                            // For large copies we copy whole words at a time. The final
                            // word is aligned to the end of the range (instead of after the
                            // previous) to handle partial words. So a copy will look like this:
                            //
                            //  ####
                            //      ####
                            //          ####
                            //            ####
                            //
                            // We handle overlap in the source and destination range by
                            // changing the copying direction. This prevents us from
                            // overwriting parts of source that we still need to copy.
                            //
                            // This correctly handles source == dest
                            //
                            if (source > dest) {
                                assembly {
                                    // We subtract 32 from `sEnd` and `dEnd` because it
                                    // is easier to compare with in the loop, and these
                                    // are also the addresses we need for copying the
                                    // last bytes.
                                    length := sub(length, 32)
                                    let sEnd := add(source, length)
                                    let dEnd := add(dest, length)
                                    // Remember the last 32 bytes of source
                                    // This needs to be done here and not after the loop
                                    // because we may have overwritten the last bytes in
                                    // source already due to overlap.
                                    let last := mload(sEnd)
                                    // Copy whole words front to back
                                    // Note: the first check is always true,
                                    // this could have been a do-while loop.
                                    // solhint-disable-next-line no-empty-blocks
                                    for {} lt(source, sEnd) {} {
                                        mstore(dest, mload(source))
                                        source := add(source, 32)
                                        dest := add(dest, 32)
                                    }
                                    // Write the last 32 bytes
                                    mstore(dEnd, last)
                                }
                            } else {
                                assembly {
                                    // We subtract 32 from `sEnd` and `dEnd` because those
                                    // are the starting points when copying a word at the end.
                                    length := sub(length, 32)
                                    let sEnd := add(source, length)
                                    let dEnd := add(dest, length)
                                    // Remember the first 32 bytes of source
                                    // This needs to be done here and not after the loop
                                    // because we may have overwritten the first bytes in
                                    // source already due to overlap.
                                    let first := mload(source)
                                    // Copy whole words back to front
                                    // We use a signed comparisson here to allow dEnd to become
                                    // negative (happens when source and dest < 32). Valid
                                    // addresses in local memory will never be larger than
                                    // 2**255, so they can be safely re-interpreted as signed.
                                    // Note: the first check is always true,
                                    // this could have been a do-while loop.
                                    // solhint-disable-next-line no-empty-blocks
                                    for {} slt(dest, dEnd) {} {
                                        mstore(dEnd, mload(sEnd))
                                        sEnd := sub(sEnd, 32)
                                        dEnd := sub(dEnd, 32)
                                    }
                                    // Write the first 32 bytes
                                    mstore(dest, first)
                                }
                            }
                        }
                    }
                    /// @dev Returns a slices from a byte array.
                    /// @param b The byte array to take a slice from.
                    /// @param from The starting index for the slice (inclusive).
                    /// @param to The final index for the slice (exclusive).
                    /// @return result The slice containing bytes at indices [from, to)
                    function slice(
                        bytes memory b,
                        uint256 from,
                        uint256 to
                    )
                        internal
                        pure
                        returns (bytes memory result)
                    {
                        // Ensure that the from and to positions are valid positions for a slice within
                        // the byte array that is being used.
                        if (from > to) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.FromLessThanOrEqualsToRequired,
                                from,
                                to
                            ));
                        }
                        if (to > b.length) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.ToLessThanOrEqualsLengthRequired,
                                to,
                                b.length
                            ));
                        }
                        // Create a new bytes structure and copy contents
                        result = new bytes(to - from);
                        memCopy(
                            result.contentAddress(),
                            b.contentAddress() + from,
                            result.length
                        );
                        return result;
                    }
                    /// @dev Returns a slice from a byte array without preserving the input.
                    ///      When `from == 0`, the original array will match the slice.
                    ///      In other cases its state will be corrupted.
                    /// @param b The byte array to take a slice from. Will be destroyed in the process.
                    /// @param from The starting index for the slice (inclusive).
                    /// @param to The final index for the slice (exclusive).
                    /// @return result The slice containing bytes at indices [from, to)
                    function sliceDestructive(
                        bytes memory b,
                        uint256 from,
                        uint256 to
                    )
                        internal
                        pure
                        returns (bytes memory result)
                    {
                        // Ensure that the from and to positions are valid positions for a slice within
                        // the byte array that is being used.
                        if (from > to) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.FromLessThanOrEqualsToRequired,
                                from,
                                to
                            ));
                        }
                        if (to > b.length) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.ToLessThanOrEqualsLengthRequired,
                                to,
                                b.length
                            ));
                        }
                        // Create a new bytes structure around [from, to) in-place.
                        assembly {
                            result := add(b, from)
                            mstore(result, sub(to, from))
                        }
                        return result;
                    }
                    /// @dev Pops the last byte off of a byte array by modifying its length.
                    /// @param b Byte array that will be modified.
                    /// @return result The byte that was popped off.
                    function popLastByte(bytes memory b)
                        internal
                        pure
                        returns (bytes1 result)
                    {
                        if (b.length == 0) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanZeroRequired,
                                b.length,
                                0
                            ));
                        }
                        // Store last byte.
                        result = b[b.length - 1];
                        assembly {
                            // Decrement length of byte array.
                            let newLen := sub(mload(b), 1)
                            mstore(b, newLen)
                        }
                        return result;
                    }
                    /// @dev Tests equality of two byte arrays.
                    /// @param lhs First byte array to compare.
                    /// @param rhs Second byte array to compare.
                    /// @return equal True if arrays are the same. False otherwise.
                    function equals(
                        bytes memory lhs,
                        bytes memory rhs
                    )
                        internal
                        pure
                        returns (bool equal)
                    {
                        // Keccak gas cost is 30 + numWords * 6. This is a cheap way to compare.
                        // We early exit on unequal lengths, but keccak would also correctly
                        // handle this.
                        return lhs.length == rhs.length && keccak256(lhs) == keccak256(rhs);
                    }
                    /// @dev Reads an address from a position in a byte array.
                    /// @param b Byte array containing an address.
                    /// @param index Index in byte array of address.
                    /// @return result address from byte array.
                    function readAddress(
                        bytes memory b,
                        uint256 index
                    )
                        internal
                        pure
                        returns (address result)
                    {
                        if (b.length < index + 20) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsTwentyRequired,
                                b.length,
                                index + 20 // 20 is length of address
                            ));
                        }
                        // Add offset to index:
                        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)
                        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)
                        index += 20;
                        // Read address from array memory
                        assembly {
                            // 1. Add index to address of bytes array
                            // 2. Load 32-byte word from memory
                            // 3. Apply 20-byte mask to obtain address
                            result := and(mload(add(b, index)), 0xffffffffffffffffffffffffffffffffffffffff)
                        }
                        return result;
                    }
                    /// @dev Writes an address into a specific position in a byte array.
                    /// @param b Byte array to insert address into.
                    /// @param index Index in byte array of address.
                    /// @param input Address to put into byte array.
                    function writeAddress(
                        bytes memory b,
                        uint256 index,
                        address input
                    )
                        internal
                        pure
                    {
                        if (b.length < index + 20) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsTwentyRequired,
                                b.length,
                                index + 20 // 20 is length of address
                            ));
                        }
                        // Add offset to index:
                        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)
                        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)
                        index += 20;
                        // Store address into array memory
                        assembly {
                            // The address occupies 20 bytes and mstore stores 32 bytes.
                            // First fetch the 32-byte word where we'll be storing the address, then
                            // apply a mask so we have only the bytes in the word that the address will not occupy.
                            // Then combine these bytes with the address and store the 32 bytes back to memory with mstore.
                            // 1. Add index to address of bytes array
                            // 2. Load 32-byte word from memory
                            // 3. Apply 12-byte mask to obtain extra bytes occupying word of memory where we'll store the address
                            let neighbors := and(
                                mload(add(b, index)),
                                0xffffffffffffffffffffffff0000000000000000000000000000000000000000
                            )
                            // Make sure input address is clean.
                            // (Solidity does not guarantee this)
                            input := and(input, 0xffffffffffffffffffffffffffffffffffffffff)
                            // Store the neighbors and address into memory
                            mstore(add(b, index), xor(input, neighbors))
                        }
                    }
                    /// @dev Reads a bytes32 value from a position in a byte array.
                    /// @param b Byte array containing a bytes32 value.
                    /// @param index Index in byte array of bytes32 value.
                    /// @return result bytes32 value from byte array.
                    function readBytes32(
                        bytes memory b,
                        uint256 index
                    )
                        internal
                        pure
                        returns (bytes32 result)
                    {
                        if (b.length < index + 32) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsThirtyTwoRequired,
                                b.length,
                                index + 32
                            ));
                        }
                        // Arrays are prefixed by a 256 bit length parameter
                        index += 32;
                        // Read the bytes32 from array memory
                        assembly {
                            result := mload(add(b, index))
                        }
                        return result;
                    }
                    /// @dev Writes a bytes32 into a specific position in a byte array.
                    /// @param b Byte array to insert <input> into.
                    /// @param index Index in byte array of <input>.
                    /// @param input bytes32 to put into byte array.
                    function writeBytes32(
                        bytes memory b,
                        uint256 index,
                        bytes32 input
                    )
                        internal
                        pure
                    {
                        if (b.length < index + 32) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsThirtyTwoRequired,
                                b.length,
                                index + 32
                            ));
                        }
                        // Arrays are prefixed by a 256 bit length parameter
                        index += 32;
                        // Read the bytes32 from array memory
                        assembly {
                            mstore(add(b, index), input)
                        }
                    }
                    /// @dev Reads a uint256 value from a position in a byte array.
                    /// @param b Byte array containing a uint256 value.
                    /// @param index Index in byte array of uint256 value.
                    /// @return result uint256 value from byte array.
                    function readUint256(
                        bytes memory b,
                        uint256 index
                    )
                        internal
                        pure
                        returns (uint256 result)
                    {
                        result = uint256(readBytes32(b, index));
                        return result;
                    }
                    /// @dev Writes a uint256 into a specific position in a byte array.
                    /// @param b Byte array to insert <input> into.
                    /// @param index Index in byte array of <input>.
                    /// @param input uint256 to put into byte array.
                    function writeUint256(
                        bytes memory b,
                        uint256 index,
                        uint256 input
                    )
                        internal
                        pure
                    {
                        writeBytes32(b, index, bytes32(input));
                    }
                    /// @dev Reads an unpadded bytes4 value from a position in a byte array.
                    /// @param b Byte array containing a bytes4 value.
                    /// @param index Index in byte array of bytes4 value.
                    /// @return result bytes4 value from byte array.
                    function readBytes4(
                        bytes memory b,
                        uint256 index
                    )
                        internal
                        pure
                        returns (bytes4 result)
                    {
                        if (b.length < index + 4) {
                            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsFourRequired,
                                b.length,
                                index + 4
                            ));
                        }
                        // Arrays are prefixed by a 32 byte length field
                        index += 32;
                        // Read the bytes4 from array memory
                        assembly {
                            result := mload(add(b, index))
                            // Solidity does not require us to clean the trailing bytes.
                            // We do it anyway
                            result := and(result, 0xFFFFFFFF00000000000000000000000000000000000000000000000000000000)
                        }
                        return result;
                    }
                    /// @dev Writes a new length to a byte array.
                    ///      Decreasing length will lead to removing the corresponding lower order bytes from the byte array.
                    ///      Increasing length may lead to appending adjacent in-memory bytes to the end of the byte array.
                    /// @param b Bytes array to write new length to.
                    /// @param length New length of byte array.
                    function writeLength(bytes memory b, uint256 length)
                        internal
                        pure
                    {
                        assembly {
                            mstore(b, length)
                        }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibBytesRichErrorsV06 {
                    enum InvalidByteOperationErrorCodes {
                        FromLessThanOrEqualsToRequired,
                        ToLessThanOrEqualsLengthRequired,
                        LengthGreaterThanZeroRequired,
                        LengthGreaterThanOrEqualsFourRequired,
                        LengthGreaterThanOrEqualsTwentyRequired,
                        LengthGreaterThanOrEqualsThirtyTwoRequired,
                        LengthGreaterThanOrEqualsNestedBytesLengthRequired,
                        DestinationLengthGreaterThanOrEqualSourceLengthRequired
                    }
                    // bytes4(keccak256("InvalidByteOperationError(uint8,uint256,uint256)"))
                    bytes4 internal constant INVALID_BYTE_OPERATION_ERROR_SELECTOR =
                        0x28006595;
                    // solhint-disable func-name-mixedcase
                    function InvalidByteOperationError(
                        InvalidByteOperationErrorCodes errorCode,
                        uint256 offset,
                        uint256 required
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            INVALID_BYTE_OPERATION_ERROR_SELECTOR,
                            errorCode,
                            offset,
                            required
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibRichErrorsV06 {
                    // bytes4(keccak256("Error(string)"))
                    bytes4 internal constant STANDARD_ERROR_SELECTOR = 0x08c379a0;
                    // solhint-disable func-name-mixedcase
                    /// @dev ABI encode a standard, string revert error payload.
                    ///      This is the same payload that would be included by a `revert(string)`
                    ///      solidity statement. It has the function signature `Error(string)`.
                    /// @param message The error string.
                    /// @return The ABI encoded error.
                    function StandardError(string memory message)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            STANDARD_ERROR_SELECTOR,
                            bytes(message)
                        );
                    }
                    // solhint-enable func-name-mixedcase
                    /// @dev Reverts an encoded rich revert reason `errorData`.
                    /// @param errorData ABI encoded error data.
                    function rrevert(bytes memory errorData)
                        internal
                        pure
                    {
                        assembly {
                            revert(add(errorData, 0x20), mload(errorData))
                        }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "../errors/LibProxyRichErrors.sol";
                library LibBootstrap {
                    /// @dev Magic bytes returned by the bootstrapper to indicate success.
                    ///      This is `keccack('BOOTSTRAP_SUCCESS')`.
                    bytes4 internal constant BOOTSTRAP_SUCCESS = 0xd150751b;
                    using LibRichErrorsV06 for bytes;
                    /// @dev Perform a delegatecall and ensure it returns the magic bytes.
                    /// @param target The call target.
                    /// @param data The call data.
                    function delegatecallBootstrapFunction(
                        address target,
                        bytes memory data
                    )
                        internal
                    {
                        (bool success, bytes memory resultData) = target.delegatecall(data);
                        if (!success ||
                            resultData.length != 32 ||
                            abi.decode(resultData, (bytes4)) != BOOTSTRAP_SUCCESS)
                        {
                            LibProxyRichErrors.BootstrapCallFailedError(target, resultData).rrevert();
                        }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibProxyRichErrors {
                    // solhint-disable func-name-mixedcase
                    function NotImplementedError(bytes4 selector)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("NotImplementedError(bytes4)")),
                            selector
                        );
                    }
                    function InvalidBootstrapCallerError(address actual, address expected)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("InvalidBootstrapCallerError(address,address)")),
                            actual,
                            expected
                        );
                    }
                    function InvalidDieCallerError(address actual, address expected)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("InvalidDieCallerError(address,address)")),
                            actual,
                            expected
                        );
                    }
                    function BootstrapCallFailedError(address target, bytes memory resultData)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("BootstrapCallFailedError(address,bytes)")),
                            target,
                            resultData
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "../migrations/LibBootstrap.sol";
                import "../storage/LibProxyStorage.sol";
                import "./IBootstrap.sol";
                /// @dev Detachable `bootstrap()` feature.
                contract Bootstrap is
                    IBootstrap
                {
                    // solhint-disable state-visibility,indent
                    /// @dev The ZeroEx contract.
                    ///      This has to be immutable to persist across delegatecalls.
                    address immutable private _deployer;
                    /// @dev The implementation address of this contract.
                    ///      This has to be immutable to persist across delegatecalls.
                    address immutable private _implementation;
                    /// @dev The deployer.
                    ///      This has to be immutable to persist across delegatecalls.
                    address immutable private _bootstrapCaller;
                    // solhint-enable state-visibility,indent
                    using LibRichErrorsV06 for bytes;
                    /// @dev Construct this contract and set the bootstrap migration contract.
                    ///      After constructing this contract, `bootstrap()` should be called
                    ///      to seed the initial feature set.
                    /// @param bootstrapCaller The allowed caller of `bootstrap()`.
                    constructor(address bootstrapCaller) public {
                        _deployer = msg.sender;
                        _implementation = address(this);
                        _bootstrapCaller = bootstrapCaller;
                    }
                    /// @dev Bootstrap the initial feature set of this contract by delegatecalling
                    ///      into `target`. Before exiting the `bootstrap()` function will
                    ///      deregister itself from the proxy to prevent being called again.
                    /// @param target The bootstrapper contract address.
                    /// @param callData The call data to execute on `target`.
                    function bootstrap(address target, bytes calldata callData) external override {
                        // Only the bootstrap caller can call this function.
                        if (msg.sender != _bootstrapCaller) {
                            LibProxyRichErrors.InvalidBootstrapCallerError(
                                msg.sender,
                                _bootstrapCaller
                            ).rrevert();
                        }
                        // Deregister.
                        LibProxyStorage.getStorage().impls[this.bootstrap.selector] = address(0);
                        // Self-destruct.
                        Bootstrap(_implementation).die();
                        // Call the bootstrapper.
                        LibBootstrap.delegatecallBootstrapFunction(target, callData);
                    }
                    /// @dev Self-destructs this contract.
                    ///      Can only be called by the deployer.
                    function die() external {
                        if (msg.sender != _deployer) {
                            LibProxyRichErrors.InvalidDieCallerError(msg.sender, _deployer).rrevert();
                        }
                        selfdestruct(msg.sender);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "./LibStorage.sol";
                /// @dev Storage helpers for the proxy contract.
                library LibProxyStorage {
                    /// @dev Storage bucket for proxy contract.
                    struct Storage {
                        // Mapping of function selector -> function implementation
                        mapping(bytes4 => address) impls;
                        // The owner of the proxy contract.
                        address owner;
                    }
                    /// @dev Get the storage bucket for this contract.
                    function getStorage() internal pure returns (Storage storage stor) {
                        uint256 storageSlot = LibStorage.getStorageSlot(
                            LibStorage.StorageId.Proxy
                        );
                        // Dip into assembly to change the slot pointed to by the local
                        // variable `stor`.
                        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                        assembly { stor_slot := storageSlot }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                /// @dev Common storage helpers
                library LibStorage {
                    /// @dev What to bit-shift a storage ID by to get its slot.
                    ///      This gives us a maximum of 2**128 inline fields in each bucket.
                    uint256 private constant STORAGE_SLOT_EXP = 128;
                    /// @dev Storage IDs for feature storage buckets.
                    ///      WARNING: APPEND-ONLY.
                    enum StorageId {
                        Proxy,
                        SimpleFunctionRegistry,
                        Ownable,
                        TokenSpender,
                        TransformERC20
                    }
                    /// @dev Get the storage slot given a storage ID. We assign unique, well-spaced
                    ///     slots to storage bucket variables to ensure they do not overlap.
                    ///     See: https://solidity.readthedocs.io/en/v0.6.6/assembly.html#access-to-external-variables-functions-and-libraries
                    /// @param storageId An entry in `StorageId`
                    /// @return slot The storage slot.
                    function getStorageSlot(StorageId storageId)
                        internal
                        pure
                        returns (uint256 slot)
                    {
                        // This should never overflow with a reasonable `STORAGE_SLOT_EXP`
                        // because Solidity will do a range check on `storageId` during the cast.
                        return (uint256(storageId) + 1) << STORAGE_SLOT_EXP;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                /// @dev Detachable `bootstrap()` feature.
                interface IBootstrap {
                    /// @dev Bootstrap the initial feature set of this contract by delegatecalling
                    ///      into `target`. Before exiting the `bootstrap()` function will
                    ///      deregister itself from the proxy to prevent being called again.
                    /// @param target The bootstrapper contract address.
                    /// @param callData The call data to execute on `target`.
                    function bootstrap(address target, bytes calldata callData) external;
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibCommonRichErrors {
                    // solhint-disable func-name-mixedcase
                    function OnlyCallableBySelfError(address sender)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("OnlyCallableBySelfError(address)")),
                            sender
                        );
                    }
                    function IllegalReentrancyError()
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("IllegalReentrancyError()"))
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibOwnableRichErrors {
                    // solhint-disable func-name-mixedcase
                    function OnlyOwnerError(
                        address sender,
                        address owner
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("OnlyOwnerError(address,address)")),
                            sender,
                            owner
                        );
                    }
                    function TransferOwnerToZeroError()
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("TransferOwnerToZeroError()"))
                        );
                    }
                    function MigrateCallFailedError(address target, bytes memory resultData)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("MigrateCallFailedError(address,bytes)")),
                            target,
                            resultData
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibSimpleFunctionRegistryRichErrors {
                    // solhint-disable func-name-mixedcase
                    function NotInRollbackHistoryError(bytes4 selector, address targetImpl)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("NotInRollbackHistoryError(bytes4,address)")),
                            selector,
                            targetImpl
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibSpenderRichErrors {
                    // solhint-disable func-name-mixedcase
                    function SpenderERC20TransferFromFailedError(
                        address token,
                        address owner,
                        address to,
                        uint256 amount,
                        bytes memory errorData
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("SpenderERC20TransferFromFailedError(address,address,address,uint256,bytes)")),
                            token,
                            owner,
                            to,
                            amount,
                            errorData
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibTransformERC20RichErrors {
                    // solhint-disable func-name-mixedcase,separate-by-one-line-in-contract
                    function InsufficientEthAttachedError(
                        uint256 ethAttached,
                        uint256 ethNeeded
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("InsufficientEthAttachedError(uint256,uint256)")),
                            ethAttached,
                            ethNeeded
                        );
                    }
                    function IncompleteTransformERC20Error(
                        address outputToken,
                        uint256 outputTokenAmount,
                        uint256 minOutputTokenAmount
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("IncompleteTransformERC20Error(address,uint256,uint256)")),
                            outputToken,
                            outputTokenAmount,
                            minOutputTokenAmount
                        );
                    }
                    function NegativeTransformERC20OutputError(
                        address outputToken,
                        uint256 outputTokenLostAmount
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("NegativeTransformERC20OutputError(address,uint256)")),
                            outputToken,
                            outputTokenLostAmount
                        );
                    }
                    function TransformerFailedError(
                        address transformer,
                        bytes memory transformerData,
                        bytes memory resultData
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("TransformerFailedError(address,bytes,bytes)")),
                            transformer,
                            transformerData,
                            resultData
                        );
                    }
                    // Common Transformer errors ///////////////////////////////////////////////
                    function OnlyCallableByDeployerError(
                        address caller,
                        address deployer
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("OnlyCallableByDeployerError(address,address)")),
                            caller,
                            deployer
                        );
                    }
                    function InvalidExecutionContextError(
                        address actualContext,
                        address expectedContext
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("InvalidExecutionContextError(address,address)")),
                            actualContext,
                            expectedContext
                        );
                    }
                    enum InvalidTransformDataErrorCode {
                        INVALID_TOKENS,
                        INVALID_ARRAY_LENGTH
                    }
                    function InvalidTransformDataError(
                        InvalidTransformDataErrorCode errorCode,
                        bytes memory transformData
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("InvalidTransformDataError(uint8,bytes)")),
                            errorCode,
                            transformData
                        );
                    }
                    // FillQuoteTransformer errors /////////////////////////////////////////////
                    function IncompleteFillSellQuoteError(
                        address sellToken,
                        uint256 soldAmount,
                        uint256 sellAmount
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("IncompleteFillSellQuoteError(address,uint256,uint256)")),
                            sellToken,
                            soldAmount,
                            sellAmount
                        );
                    }
                    function IncompleteFillBuyQuoteError(
                        address buyToken,
                        uint256 boughtAmount,
                        uint256 buyAmount
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("IncompleteFillBuyQuoteError(address,uint256,uint256)")),
                            buyToken,
                            boughtAmount,
                            buyAmount
                        );
                    }
                    function InsufficientTakerTokenError(
                        uint256 tokenBalance,
                        uint256 tokensNeeded
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("InsufficientTakerTokenError(uint256,uint256)")),
                            tokenBalance,
                            tokensNeeded
                        );
                    }
                    function InsufficientProtocolFeeError(
                        uint256 ethBalance,
                        uint256 ethNeeded
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("InsufficientProtocolFeeError(uint256,uint256)")),
                            ethBalance,
                            ethNeeded
                        );
                    }
                    function InvalidERC20AssetDataError(
                        bytes memory assetData
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("InvalidERC20AssetDataError(bytes)")),
                            assetData
                        );
                    }
                    function InvalidTakerFeeTokenError(
                        address token
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("InvalidTakerFeeTokenError(address)")),
                            token
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibWalletRichErrors {
                    // solhint-disable func-name-mixedcase
                    function WalletExecuteCallFailedError(
                        address wallet,
                        address callTarget,
                        bytes memory callData,
                        uint256 callValue,
                        bytes memory errorData
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("WalletExecuteCallFailedError(address,address,bytes,uint256,bytes)")),
                            wallet,
                            callTarget,
                            callData,
                            callValue,
                            errorData
                        );
                    }
                    function WalletExecuteDelegateCallFailedError(
                        address wallet,
                        address callTarget,
                        bytes memory callData,
                        bytes memory errorData
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            bytes4(keccak256("WalletExecuteDelegateCallFailedError(address,address,bytes,bytes)")),
                            wallet,
                            callTarget,
                            callData,
                            errorData
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/AuthorizableV06.sol";
                import "../errors/LibSpenderRichErrors.sol";
                import "./IAllowanceTarget.sol";
                /// @dev The allowance target for the TokenSpender feature.
                contract AllowanceTarget is
                    IAllowanceTarget,
                    AuthorizableV06
                {
                    // solhint-disable no-unused-vars,indent,no-empty-blocks
                    using LibRichErrorsV06 for bytes;
                    /// @dev Execute an arbitrary call. Only an authority can call this.
                    /// @param target The call target.
                    /// @param callData The call data.
                    /// @return resultData The data returned by the call.
                    function executeCall(
                        address payable target,
                        bytes calldata callData
                    )
                        external
                        override
                        onlyAuthorized
                        returns (bytes memory resultData)
                    {
                        bool success;
                        (success, resultData) = target.call(callData);
                        if (!success) {
                            resultData.rrevert();
                        }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "./interfaces/IAuthorizableV06.sol";
                import "./errors/LibRichErrorsV06.sol";
                import "./errors/LibAuthorizableRichErrorsV06.sol";
                import "./OwnableV06.sol";
                // solhint-disable no-empty-blocks
                contract AuthorizableV06 is
                    OwnableV06,
                    IAuthorizableV06
                {
                    /// @dev Only authorized addresses can invoke functions with this modifier.
                    modifier onlyAuthorized {
                        _assertSenderIsAuthorized();
                        _;
                    }
                    // @dev Whether an address is authorized to call privileged functions.
                    // @param 0 Address to query.
                    // @return 0 Whether the address is authorized.
                    mapping (address => bool) public override authorized;
                    // @dev Whether an address is authorized to call privileged functions.
                    // @param 0 Index of authorized address.
                    // @return 0 Authorized address.
                    address[] public override authorities;
                    /// @dev Initializes the `owner` address.
                    constructor()
                        public
                        OwnableV06()
                    {}
                    /// @dev Authorizes an address.
                    /// @param target Address to authorize.
                    function addAuthorizedAddress(address target)
                        external
                        override
                        onlyOwner
                    {
                        _addAuthorizedAddress(target);
                    }
                    /// @dev Removes authorizion of an address.
                    /// @param target Address to remove authorization from.
                    function removeAuthorizedAddress(address target)
                        external
                        override
                        onlyOwner
                    {
                        if (!authorized[target]) {
                            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.TargetNotAuthorizedError(target));
                        }
                        for (uint256 i = 0; i < authorities.length; i++) {
                            if (authorities[i] == target) {
                                _removeAuthorizedAddressAtIndex(target, i);
                                break;
                            }
                        }
                    }
                    /// @dev Removes authorizion of an address.
                    /// @param target Address to remove authorization from.
                    /// @param index Index of target in authorities array.
                    function removeAuthorizedAddressAtIndex(
                        address target,
                        uint256 index
                    )
                        external
                        override
                        onlyOwner
                    {
                        _removeAuthorizedAddressAtIndex(target, index);
                    }
                    /// @dev Gets all authorized addresses.
                    /// @return Array of authorized addresses.
                    function getAuthorizedAddresses()
                        external
                        override
                        view
                        returns (address[] memory)
                    {
                        return authorities;
                    }
                    /// @dev Reverts if msg.sender is not authorized.
                    function _assertSenderIsAuthorized()
                        internal
                        view
                    {
                        if (!authorized[msg.sender]) {
                            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.SenderNotAuthorizedError(msg.sender));
                        }
                    }
                    /// @dev Authorizes an address.
                    /// @param target Address to authorize.
                    function _addAuthorizedAddress(address target)
                        internal
                    {
                        // Ensure that the target is not the zero address.
                        if (target == address(0)) {
                            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.ZeroCantBeAuthorizedError());
                        }
                        // Ensure that the target is not already authorized.
                        if (authorized[target]) {
                            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.TargetAlreadyAuthorizedError(target));
                        }
                        authorized[target] = true;
                        authorities.push(target);
                        emit AuthorizedAddressAdded(target, msg.sender);
                    }
                    /// @dev Removes authorizion of an address.
                    /// @param target Address to remove authorization from.
                    /// @param index Index of target in authorities array.
                    function _removeAuthorizedAddressAtIndex(
                        address target,
                        uint256 index
                    )
                        internal
                    {
                        if (!authorized[target]) {
                            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.TargetNotAuthorizedError(target));
                        }
                        if (index >= authorities.length) {
                            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.IndexOutOfBoundsError(
                                index,
                                authorities.length
                            ));
                        }
                        if (authorities[index] != target) {
                            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.AuthorizedAddressMismatchError(
                                authorities[index],
                                target
                            ));
                        }
                        delete authorized[target];
                        authorities[index] = authorities[authorities.length - 1];
                        authorities.pop();
                        emit AuthorizedAddressRemoved(target, msg.sender);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "./IOwnableV06.sol";
                interface IAuthorizableV06 is
                    IOwnableV06
                {
                    // Event logged when a new address is authorized.
                    event AuthorizedAddressAdded(
                        address indexed target,
                        address indexed caller
                    );
                    // Event logged when a currently authorized address is unauthorized.
                    event AuthorizedAddressRemoved(
                        address indexed target,
                        address indexed caller
                    );
                    /// @dev Authorizes an address.
                    /// @param target Address to authorize.
                    function addAuthorizedAddress(address target)
                        external;
                    /// @dev Removes authorizion of an address.
                    /// @param target Address to remove authorization from.
                    function removeAuthorizedAddress(address target)
                        external;
                    /// @dev Removes authorizion of an address.
                    /// @param target Address to remove authorization from.
                    /// @param index Index of target in authorities array.
                    function removeAuthorizedAddressAtIndex(
                        address target,
                        uint256 index
                    )
                        external;
                    /// @dev Gets all authorized addresses.
                    /// @return authorizedAddresses Array of authorized addresses.
                    function getAuthorizedAddresses()
                        external
                        view
                        returns (address[] memory authorizedAddresses);
                    /// @dev Whether an adderss is authorized to call privileged functions.
                    /// @param addr Address to query.
                    /// @return isAuthorized Whether the address is authorized.
                    function authorized(address addr) external view returns (bool isAuthorized);
                    /// @dev All addresseses authorized to call privileged functions.
                    /// @param idx Index of authorized address.
                    /// @return addr Authorized address.
                    function authorities(uint256 idx) external view returns (address addr);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                interface IOwnableV06 {
                    /// @dev Emitted by Ownable when ownership is transferred.
                    /// @param previousOwner The previous owner of the contract.
                    /// @param newOwner The new owner of the contract.
                    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                    /// @dev Transfers ownership of the contract to a new address.
                    /// @param newOwner The address that will become the owner.
                    function transferOwnership(address newOwner) external;
                    /// @dev The owner of this contract.
                    /// @return ownerAddress The owner address.
                    function owner() external view returns (address ownerAddress);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibAuthorizableRichErrorsV06 {
                    // bytes4(keccak256("AuthorizedAddressMismatchError(address,address)"))
                    bytes4 internal constant AUTHORIZED_ADDRESS_MISMATCH_ERROR_SELECTOR =
                        0x140a84db;
                    // bytes4(keccak256("IndexOutOfBoundsError(uint256,uint256)"))
                    bytes4 internal constant INDEX_OUT_OF_BOUNDS_ERROR_SELECTOR =
                        0xe9f83771;
                    // bytes4(keccak256("SenderNotAuthorizedError(address)"))
                    bytes4 internal constant SENDER_NOT_AUTHORIZED_ERROR_SELECTOR =
                        0xb65a25b9;
                    // bytes4(keccak256("TargetAlreadyAuthorizedError(address)"))
                    bytes4 internal constant TARGET_ALREADY_AUTHORIZED_ERROR_SELECTOR =
                        0xde16f1a0;
                    // bytes4(keccak256("TargetNotAuthorizedError(address)"))
                    bytes4 internal constant TARGET_NOT_AUTHORIZED_ERROR_SELECTOR =
                        0xeb5108a2;
                    // bytes4(keccak256("ZeroCantBeAuthorizedError()"))
                    bytes internal constant ZERO_CANT_BE_AUTHORIZED_ERROR_BYTES =
                        hex"57654fe4";
                    // solhint-disable func-name-mixedcase
                    function AuthorizedAddressMismatchError(
                        address authorized,
                        address target
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            AUTHORIZED_ADDRESS_MISMATCH_ERROR_SELECTOR,
                            authorized,
                            target
                        );
                    }
                    function IndexOutOfBoundsError(
                        uint256 index,
                        uint256 length
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            INDEX_OUT_OF_BOUNDS_ERROR_SELECTOR,
                            index,
                            length
                        );
                    }
                    function SenderNotAuthorizedError(address sender)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            SENDER_NOT_AUTHORIZED_ERROR_SELECTOR,
                            sender
                        );
                    }
                    function TargetAlreadyAuthorizedError(address target)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            TARGET_ALREADY_AUTHORIZED_ERROR_SELECTOR,
                            target
                        );
                    }
                    function TargetNotAuthorizedError(address target)
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            TARGET_NOT_AUTHORIZED_ERROR_SELECTOR,
                            target
                        );
                    }
                    function ZeroCantBeAuthorizedError()
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return ZERO_CANT_BE_AUTHORIZED_ERROR_BYTES;
                    }
                }
                /*
                  Copyright 2019 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "./interfaces/IOwnableV06.sol";
                import "./errors/LibRichErrorsV06.sol";
                import "./errors/LibOwnableRichErrorsV06.sol";
                contract OwnableV06 is
                    IOwnableV06
                {
                    /// @dev The owner of this contract.
                    /// @return 0 The owner address.
                    address public override owner;
                    constructor() public {
                        owner = msg.sender;
                    }
                    modifier onlyOwner() {
                        _assertSenderIsOwner();
                        _;
                    }
                    /// @dev Change the owner of this contract.
                    /// @param newOwner New owner address.
                    function transferOwnership(address newOwner)
                        public
                        override
                        onlyOwner
                    {
                        if (newOwner == address(0)) {
                            LibRichErrorsV06.rrevert(LibOwnableRichErrorsV06.TransferOwnerToZeroError());
                        } else {
                            owner = newOwner;
                            emit OwnershipTransferred(msg.sender, newOwner);
                        }
                    }
                    function _assertSenderIsOwner()
                        internal
                        view
                    {
                        if (msg.sender != owner) {
                            LibRichErrorsV06.rrevert(LibOwnableRichErrorsV06.OnlyOwnerError(
                                msg.sender,
                                owner
                            ));
                        }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibOwnableRichErrorsV06 {
                    // bytes4(keccak256("OnlyOwnerError(address,address)"))
                    bytes4 internal constant ONLY_OWNER_ERROR_SELECTOR =
                        0x1de45ad1;
                    // bytes4(keccak256("TransferOwnerToZeroError()"))
                    bytes internal constant TRANSFER_OWNER_TO_ZERO_ERROR_BYTES =
                        hex"e69edc3e";
                    // solhint-disable func-name-mixedcase
                    function OnlyOwnerError(
                        address sender,
                        address owner
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            ONLY_OWNER_ERROR_SELECTOR,
                            sender,
                            owner
                        );
                    }
                    function TransferOwnerToZeroError()
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return TRANSFER_OWNER_TO_ZERO_ERROR_BYTES;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/interfaces/IAuthorizableV06.sol";
                /// @dev The allowance target for the TokenSpender feature.
                interface IAllowanceTarget is
                    IAuthorizableV06
                {
                    /// @dev Execute an arbitrary call. Only an authority can call this.
                    /// @param target The call target.
                    /// @param callData The call data.
                    /// @return resultData The data returned by the call.
                    function executeCall(
                        address payable target,
                        bytes calldata callData
                    )
                        external
                        returns (bytes memory resultData);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/errors/LibOwnableRichErrorsV06.sol";
                import "../errors/LibWalletRichErrors.sol";
                import "./IFlashWallet.sol";
                /// @dev A contract that can execute arbitrary calls from its owner.
                contract FlashWallet is
                    IFlashWallet
                {
                    // solhint-disable no-unused-vars,indent,no-empty-blocks
                    using LibRichErrorsV06 for bytes;
                    // solhint-disable
                    /// @dev Store the owner/deployer as an immutable to make this contract stateless.
                    address public override immutable owner;
                    // solhint-enable
                    constructor() public {
                        // The deployer is the owner.
                        owner = msg.sender;
                    }
                    /// @dev Allows only the (immutable) owner to call a function.
                    modifier onlyOwner() virtual {
                        if (msg.sender != owner) {
                            LibOwnableRichErrorsV06.OnlyOwnerError(
                                msg.sender,
                                owner
                            ).rrevert();
                        }
                        _;
                    }
                    /// @dev Execute an arbitrary call. Only an authority can call this.
                    /// @param target The call target.
                    /// @param callData The call data.
                    /// @param value Ether to attach to the call.
                    /// @return resultData The data returned by the call.
                    function executeCall(
                        address payable target,
                        bytes calldata callData,
                        uint256 value
                    )
                        external
                        payable
                        override
                        onlyOwner
                        returns (bytes memory resultData)
                    {
                        bool success;
                        (success, resultData) = target.call{value: value}(callData);
                        if (!success) {
                            LibWalletRichErrors
                                .WalletExecuteCallFailedError(
                                    address(this),
                                    target,
                                    callData,
                                    value,
                                    resultData
                                )
                                .rrevert();
                        }
                    }
                    /// @dev Execute an arbitrary delegatecall, in the context of this puppet.
                    ///      Only an authority can call this.
                    /// @param target The call target.
                    /// @param callData The call data.
                    /// @return resultData The data returned by the call.
                    function executeDelegateCall(
                        address payable target,
                        bytes calldata callData
                    )
                        external
                        payable
                        override
                        onlyOwner
                        returns (bytes memory resultData)
                    {
                        bool success;
                        (success, resultData) = target.delegatecall(callData);
                        if (!success) {
                            LibWalletRichErrors
                                .WalletExecuteDelegateCallFailedError(
                                    address(this),
                                    target,
                                    callData,
                                    resultData
                                )
                                .rrevert();
                        }
                    }
                    // solhint-disable
                    /// @dev Allows this contract to receive ether.
                    receive() external override payable {}
                    // solhint-enable
                    /// @dev Signal support for receiving ERC1155 tokens.
                    /// @param interfaceID The interface ID, as per ERC-165 rules.
                    /// @return hasSupport `true` if this contract supports an ERC-165 interface.
                    function supportsInterface(bytes4 interfaceID)
                        external
                        pure
                        returns (bool hasSupport)
                    {
                        return  interfaceID == this.supportsInterface.selector ||
                                interfaceID == this.onERC1155Received.selector ^ this.onERC1155BatchReceived.selector ||
                                interfaceID == this.tokenFallback.selector;
                    }
                    ///  @dev Allow this contract to receive ERC1155 tokens.
                    ///  @return success  `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
                    function onERC1155Received(
                        address, // operator,
                        address, // from,
                        uint256, // id,
                        uint256, // value,
                        bytes calldata //data
                    )
                        external
                        pure
                        returns (bytes4 success)
                    {
                        return this.onERC1155Received.selector;
                    }
                    ///  @dev Allow this contract to receive ERC1155 tokens.
                    ///  @return success  `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
                    function onERC1155BatchReceived(
                        address, // operator,
                        address, // from,
                        uint256[] calldata, // ids,
                        uint256[] calldata, // values,
                        bytes calldata // data
                    )
                        external
                        pure
                        returns (bytes4 success)
                    {
                        return this.onERC1155BatchReceived.selector;
                    }
                    /// @dev Allows this contract to receive ERC223 tokens.
                    function tokenFallback(
                        address, // from,
                        uint256, // value,
                        bytes calldata // value
                    )
                        external
                        pure
                    {}
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/interfaces/IOwnableV06.sol";
                /// @dev A contract that can execute arbitrary calls from its owner.
                interface IFlashWallet {
                    /// @dev Execute an arbitrary call. Only an authority can call this.
                    /// @param target The call target.
                    /// @param callData The call data.
                    /// @param value Ether to attach to the call.
                    /// @return resultData The data returned by the call.
                    function executeCall(
                        address payable target,
                        bytes calldata callData,
                        uint256 value
                    )
                        external
                        payable
                        returns (bytes memory resultData);
                    /// @dev Execute an arbitrary delegatecall, in the context of this puppet.
                    ///      Only an authority can call this.
                    /// @param target The call target.
                    /// @param callData The call data.
                    /// @return resultData The data returned by the call.
                    function executeDelegateCall(
                        address payable target,
                        bytes calldata callData
                    )
                        external
                        payable
                        returns (bytes memory resultData);
                    /// @dev Allows the puppet to receive ETH.
                    receive() external payable;
                    /// @dev Fetch the immutable owner/deployer of this contract.
                    /// @return owner_ The immutable owner/deployer/
                    function owner() external view returns (address owner_);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/AuthorizableV06.sol";
                /// @dev A contract with a `die()` function.
                interface IKillable {
                    function die() external;
                }
                /// @dev Deployer contract for ERC20 transformers.
                ///      Only authorities may call `deploy()` and `kill()`.
                contract TransformerDeployer is
                    AuthorizableV06
                {
                    /// @dev Emitted when a contract is deployed via `deploy()`.
                    /// @param deployedAddress The address of the deployed contract.
                    /// @param nonce The deployment nonce.
                    /// @param sender The caller of `deploy()`.
                    event Deployed(address deployedAddress, uint256 nonce, address sender);
                    /// @dev Emitted when a contract is killed via `kill()`.
                    /// @param target The address of the contract being killed..
                    /// @param sender The caller of `kill()`.
                    event Killed(address target, address sender);
                    // @dev The current nonce of this contract.
                    uint256 public nonce = 1;
                    // @dev Mapping of deployed contract address to deployment nonce.
                    mapping (address => uint256) public toDeploymentNonce;
                    /// @dev Create this contract and register authorities.
                    constructor(address[] memory authorities) public {
                        for (uint256 i = 0; i < authorities.length; ++i) {
                            _addAuthorizedAddress(authorities[i]);
                        }
                    }
                    /// @dev Deploy a new contract. Only callable by an authority.
                    ///      Any attached ETH will also be forwarded.
                    function deploy(bytes memory bytecode)
                        public
                        payable
                        onlyAuthorized
                        returns (address deployedAddress)
                    {
                        uint256 deploymentNonce = nonce;
                        nonce += 1;
                        assembly {
                            deployedAddress := create(callvalue(), add(bytecode, 32), mload(bytecode))
                        }
                        toDeploymentNonce[deployedAddress] = deploymentNonce;
                        emit Deployed(deployedAddress, deploymentNonce, msg.sender);
                    }
                    /// @dev Call `die()` on a contract. Only callable by an authority.
                    function kill(IKillable target)
                        public
                        onlyAuthorized
                    {
                        target.die();
                        emit Killed(address(target), msg.sender);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                /// @dev Basic interface for a feature contract.
                interface IFeature {
                    // solhint-disable func-name-mixedcase
                    /// @dev The name of this feature set.
                    function FEATURE_NAME() external view returns (string memory name);
                    /// @dev The version of this feature set.
                    function FEATURE_VERSION() external view returns (uint256 version);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/interfaces/IOwnableV06.sol";
                // solhint-disable no-empty-blocks
                /// @dev Owner management and migration features.
                interface IOwnable is
                    IOwnableV06
                {
                    /// @dev Emitted when `migrate()` is called.
                    /// @param caller The caller of `migrate()`.
                    /// @param migrator The migration contract.
                    /// @param newOwner The address of the new owner.
                    event Migrated(address caller, address migrator, address newOwner);
                    /// @dev Execute a migration function in the context of the ZeroEx contract.
                    ///      The result of the function being called should be the magic bytes
                    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
                    ///      The owner will be temporarily set to `address(this)` inside the call.
                    ///      Before returning, the owner will be set to `newOwner`.
                    /// @param target The migrator contract address.
                    /// @param newOwner The address of the new owner.
                    /// @param data The call data.
                    function migrate(address target, bytes calldata data, address newOwner) external;
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                /// @dev Basic registry management features.
                interface ISimpleFunctionRegistry {
                    /// @dev A function implementation was updated via `extend()` or `rollback()`.
                    /// @param selector The function selector.
                    /// @param oldImpl The implementation contract address being replaced.
                    /// @param newImpl The replacement implementation contract address.
                    event ProxyFunctionUpdated(bytes4 indexed selector, address oldImpl, address newImpl);
                    /// @dev Roll back to a prior implementation of a function.
                    /// @param selector The function selector.
                    /// @param targetImpl The address of an older implementation of the function.
                    function rollback(bytes4 selector, address targetImpl) external;
                    /// @dev Register or replace a function.
                    /// @param selector The function selector.
                    /// @param impl The implementation contract for the function.
                    function extend(bytes4 selector, address impl) external;
                    /// @dev Retrieve the length of the rollback history for a function.
                    /// @param selector The function selector.
                    /// @return rollbackLength The number of items in the rollback history for
                    ///         the function.
                    function getRollbackLength(bytes4 selector)
                        external
                        view
                        returns (uint256 rollbackLength);
                    /// @dev Retrieve an entry in the rollback history for a function.
                    /// @param selector The function selector.
                    /// @param idx The index in the rollback history.
                    /// @return impl An implementation address for the function at
                    ///         index `idx`.
                    function getRollbackEntryAtIndex(bytes4 selector, uint256 idx)
                        external
                        view
                        returns (address impl);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                /// @dev Feature that allows spending token allowances.
                interface ITokenSpender {
                    /// @dev Transfers ERC20 tokens from `owner` to `to`.
                    ///      Only callable from within.
                    /// @param token The token to spend.
                    /// @param owner The owner of the tokens.
                    /// @param to The recipient of the tokens.
                    /// @param amount The amount of `token` to transfer.
                    function _spendERC20Tokens(
                        IERC20TokenV06 token,
                        address owner,
                        address to,
                        uint256 amount
                    )
                        external;
                    /// @dev Gets the maximum amount of an ERC20 token `token` that can be
                    ///      pulled from `owner`.
                    /// @param token The token to spend.
                    /// @param owner The owner of the tokens.
                    /// @return amount The amount of tokens that can be pulled.
                    function getSpendableERC20BalanceOf(IERC20TokenV06 token, address owner)
                        external
                        view
                        returns (uint256 amount);
                    /// @dev Get the address of the allowance target.
                    /// @return target The target of token allowances.
                    function getAllowanceTarget() external view returns (address target);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                interface IERC20TokenV06 {
                    // solhint-disable no-simple-event-func-name
                    event Transfer(
                        address indexed from,
                        address indexed to,
                        uint256 value
                    );
                    event Approval(
                        address indexed owner,
                        address indexed spender,
                        uint256 value
                    );
                    /// @dev send `value` token to `to` from `msg.sender`
                    /// @param to The address of the recipient
                    /// @param value The amount of token to be transferred
                    /// @return True if transfer was successful
                    function transfer(address to, uint256 value)
                        external
                        returns (bool);
                    /// @dev send `value` token to `to` from `from` on the condition it is approved by `from`
                    /// @param from The address of the sender
                    /// @param to The address of the recipient
                    /// @param value The amount of token to be transferred
                    /// @return True if transfer was successful
                    function transferFrom(
                        address from,
                        address to,
                        uint256 value
                    )
                        external
                        returns (bool);
                    /// @dev `msg.sender` approves `spender` to spend `value` tokens
                    /// @param spender The address of the account able to transfer the tokens
                    /// @param value The amount of wei to be approved for transfer
                    /// @return Always true if the call has enough gas to complete execution
                    function approve(address spender, uint256 value)
                        external
                        returns (bool);
                    /// @dev Query total supply of token
                    /// @return Total supply of token
                    function totalSupply()
                        external
                        view
                        returns (uint256);
                    /// @dev Get the balance of `owner`.
                    /// @param owner The address from which the balance will be retrieved
                    /// @return Balance of owner
                    function balanceOf(address owner)
                        external
                        view
                        returns (uint256);
                    /// @dev Get the allowance for `spender` to spend from `owner`.
                    /// @param owner The address of the account owning tokens
                    /// @param spender The address of the account able to transfer the tokens
                    /// @return Amount of remaining tokens allowed to spent
                    function allowance(address owner, address spender)
                        external
                        view
                        returns (uint256);
                    /// @dev Get the number of decimals this token has.
                    function decimals()
                        external
                        view
                        returns (uint8);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                import "../transformers/IERC20Transformer.sol";
                import "../external/IFlashWallet.sol";
                /// @dev Feature to composably transform between ERC20 tokens.
                interface ITransformERC20 {
                    /// @dev Defines a transformation to run in `transformERC20()`.
                    struct Transformation {
                        // The deployment nonce for the transformer.
                        // The address of the transformer contract will be derived from this
                        // value.
                        uint32 deploymentNonce;
                        // Arbitrary data to pass to the transformer.
                        bytes data;
                    }
                    /// @dev Raised upon a successful `transformERC20`.
                    /// @param taker The taker (caller) address.
                    /// @param inputToken The token being provided by the taker.
                    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
                    /// @param outputToken The token to be acquired by the taker.
                    ///        `0xeee...` implies ETH.
                    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
                    /// @param outputTokenAmount The amount of `outputToken` received by the taker.
                    event TransformedERC20(
                        address indexed taker,
                        address inputToken,
                        address outputToken,
                        uint256 inputTokenAmount,
                        uint256 outputTokenAmount
                    );
                    /// @dev Raised when `setTransformerDeployer()` is called.
                    /// @param transformerDeployer The new deployer address.
                    event TransformerDeployerUpdated(address transformerDeployer);
                    /// @dev Replace the allowed deployer for transformers.
                    ///      Only callable by the owner.
                    /// @param transformerDeployer The address of the trusted deployer for transformers.
                    function setTransformerDeployer(address transformerDeployer)
                        external;
                    /// @dev Deploy a new flash wallet instance and replace the current one with it.
                    ///      Useful if we somehow break the current wallet instance.
                    ///      Anyone can call this.
                    /// @return wallet The new wallet instance.
                    function createTransformWallet()
                        external
                        returns (IFlashWallet wallet);
                    /// @dev Executes a series of transformations to convert an ERC20 `inputToken`
                    ///      to an ERC20 `outputToken`.
                    /// @param inputToken The token being provided by the sender.
                    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
                    /// @param outputToken The token to be acquired by the sender.
                    ///        `0xeee...` implies ETH.
                    /// @param inputTokenAmount The amount of `inputToken` to take from the sender.
                    /// @param minOutputTokenAmount The minimum amount of `outputToken` the sender
                    ///        must receive for the entire transformation to succeed.
                    /// @param transformations The transformations to execute on the token balance(s)
                    ///        in sequence.
                    /// @return outputTokenAmount The amount of `outputToken` received by the sender.
                    function transformERC20(
                        IERC20TokenV06 inputToken,
                        IERC20TokenV06 outputToken,
                        uint256 inputTokenAmount,
                        uint256 minOutputTokenAmount,
                        Transformation[] calldata transformations
                    )
                        external
                        payable
                        returns (uint256 outputTokenAmount);
                    /// @dev Internal version of `transformERC20()`. Only callable from within.
                    /// @param callDataHash Hash of the ingress calldata.
                    /// @param taker The taker address.
                    /// @param inputToken The token being provided by the taker.
                    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
                    /// @param outputToken The token to be acquired by the taker.
                    ///        `0xeee...` implies ETH.
                    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
                    /// @param minOutputTokenAmount The minimum amount of `outputToken` the taker
                    ///        must receive for the entire transformation to succeed.
                    /// @param transformations The transformations to execute on the token balance(s)
                    ///        in sequence.
                    /// @return outputTokenAmount The amount of `outputToken` received by the taker.
                    function _transformERC20(
                        bytes32 callDataHash,
                        address payable taker,
                        IERC20TokenV06 inputToken,
                        IERC20TokenV06 outputToken,
                        uint256 inputTokenAmount,
                        uint256 minOutputTokenAmount,
                        Transformation[] calldata transformations
                    )
                        external
                        payable
                        returns (uint256 outputTokenAmount);
                    /// @dev Return the current wallet instance that will serve as the execution
                    ///      context for transformations.
                    /// @return wallet The wallet instance.
                    function getTransformWallet()
                        external
                        view
                        returns (IFlashWallet wallet);
                    /// @dev Return the allowed deployer for transformers.
                    /// @return deployer The transform deployer address.
                    function getTransformerDeployer()
                        external
                        view
                        returns (address deployer);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                /// @dev A transformation callback used in `TransformERC20.transformERC20()`.
                interface IERC20Transformer {
                    /// @dev Called from `TransformERC20.transformERC20()`. This will be
                    ///      delegatecalled in the context of the FlashWallet instance being used.
                    /// @param callDataHash The hash of the `TransformERC20.transformERC20()` calldata.
                    /// @param taker The taker address (caller of `TransformERC20.transformERC20()`).
                    /// @param data Arbitrary data to pass to the transformer.
                    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
                    function transform(
                        bytes32 callDataHash,
                        address payable taker,
                        bytes calldata data
                    )
                        external
                        returns (bytes4 success);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "../fixins/FixinCommon.sol";
                import "../errors/LibOwnableRichErrors.sol";
                import "../storage/LibOwnableStorage.sol";
                import "../migrations/LibBootstrap.sol";
                import "../migrations/LibMigrate.sol";
                import "./IFeature.sol";
                import "./IOwnable.sol";
                import "./SimpleFunctionRegistry.sol";
                /// @dev Owner management features.
                contract Ownable is
                    IFeature,
                    IOwnable,
                    FixinCommon
                {
                    // solhint-disable
                    /// @dev Name of this feature.
                    string public constant override FEATURE_NAME = "Ownable";
                    /// @dev Version of this feature.
                    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
                    /// @dev The deployed address of this contract.
                    address immutable private _implementation;
                    // solhint-enable
                    using LibRichErrorsV06 for bytes;
                    constructor() public {
                        _implementation = address(this);
                    }
                    /// @dev Initializes this feature. The intial owner will be set to this (ZeroEx)
                    ///      to allow the bootstrappers to call `extend()`. Ownership should be
                    ///      transferred to the real owner by the bootstrapper after
                    ///      bootstrapping is complete.
                    /// @return success Magic bytes if successful.
                    function bootstrap() external returns (bytes4 success) {
                        // Set the owner to ourselves to allow bootstrappers to call `extend()`.
                        LibOwnableStorage.getStorage().owner = address(this);
                        // Register feature functions.
                        SimpleFunctionRegistry(address(this))._extendSelf(this.transferOwnership.selector, _implementation);
                        SimpleFunctionRegistry(address(this))._extendSelf(this.owner.selector, _implementation);
                        SimpleFunctionRegistry(address(this))._extendSelf(this.migrate.selector, _implementation);
                        return LibBootstrap.BOOTSTRAP_SUCCESS;
                    }
                    /// @dev Change the owner of this contract.
                    ///      Only directly callable by the owner.
                    /// @param newOwner New owner address.
                    function transferOwnership(address newOwner)
                        external
                        override
                        onlyOwner
                    {
                        LibOwnableStorage.Storage storage proxyStor = LibOwnableStorage.getStorage();
                        if (newOwner == address(0)) {
                            LibOwnableRichErrors.TransferOwnerToZeroError().rrevert();
                        } else {
                            proxyStor.owner = newOwner;
                            emit OwnershipTransferred(msg.sender, newOwner);
                        }
                    }
                    /// @dev Execute a migration function in the context of the ZeroEx contract.
                    ///      The result of the function being called should be the magic bytes
                    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
                    ///      Temporarily sets the owner to ourselves so we can perform admin functions.
                    ///      Before returning, the owner will be set to `newOwner`.
                    /// @param target The migrator contract address.
                    /// @param data The call data.
                    /// @param newOwner The address of the new owner.
                    function migrate(address target, bytes calldata data, address newOwner)
                        external
                        override
                        onlyOwner
                    {
                        if (newOwner == address(0)) {
                            LibOwnableRichErrors.TransferOwnerToZeroError().rrevert();
                        }
                        LibOwnableStorage.Storage storage stor = LibOwnableStorage.getStorage();
                        // The owner will be temporarily set to `address(this)` inside the call.
                        stor.owner = address(this);
                        // Perform the migration.
                        LibMigrate.delegatecallMigrateFunction(target, data);
                        // Update the owner.
                        stor.owner = newOwner;
                        emit Migrated(msg.sender, target, newOwner);
                    }
                    /// @dev Get the owner of this contract.
                    /// @return owner_ The owner of this contract.
                    function owner() external override view returns (address owner_) {
                        return LibOwnableStorage.getStorage().owner;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "../errors/LibCommonRichErrors.sol";
                import "../errors/LibOwnableRichErrors.sol";
                import "../features/IOwnable.sol";
                /// @dev Common feature utilities.
                contract FixinCommon {
                    using LibRichErrorsV06 for bytes;
                    /// @dev The caller must be this contract.
                    modifier onlySelf() virtual {
                        if (msg.sender != address(this)) {
                            LibCommonRichErrors.OnlyCallableBySelfError(msg.sender).rrevert();
                        }
                        _;
                    }
                    /// @dev The caller of this function must be the owner.
                    modifier onlyOwner() virtual {
                        {
                            address owner = IOwnable(address(this)).owner();
                            if (msg.sender != owner) {
                                LibOwnableRichErrors.OnlyOwnerError(
                                    msg.sender,
                                    owner
                                ).rrevert();
                            }
                        }
                        _;
                    }
                    /// @dev Encode a feature version as a `uint256`.
                    /// @param major The major version number of the feature.
                    /// @param minor The minor version number of the feature.
                    /// @param revision The revision number of the feature.
                    /// @return encodedVersion The encoded version number.
                    function _encodeVersion(uint32 major, uint32 minor, uint32 revision)
                        internal
                        pure
                        returns (uint256 encodedVersion)
                    {
                        return (major << 64) | (minor << 32) | revision;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "./LibStorage.sol";
                /// @dev Storage helpers for the `Ownable` feature.
                library LibOwnableStorage {
                    /// @dev Storage bucket for this feature.
                    struct Storage {
                        // The owner of this contract.
                        address owner;
                    }
                    /// @dev Get the storage bucket for this contract.
                    function getStorage() internal pure returns (Storage storage stor) {
                        uint256 storageSlot = LibStorage.getStorageSlot(
                            LibStorage.StorageId.Ownable
                        );
                        // Dip into assembly to change the slot pointed to by the local
                        // variable `stor`.
                        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                        assembly { stor_slot := storageSlot }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "../errors/LibOwnableRichErrors.sol";
                library LibMigrate {
                    /// @dev Magic bytes returned by a migrator to indicate success.
                    ///      This is `keccack('MIGRATE_SUCCESS')`.
                    bytes4 internal constant MIGRATE_SUCCESS = 0x2c64c5ef;
                    using LibRichErrorsV06 for bytes;
                    /// @dev Perform a delegatecall and ensure it returns the magic bytes.
                    /// @param target The call target.
                    /// @param data The call data.
                    function delegatecallMigrateFunction(
                        address target,
                        bytes memory data
                    )
                        internal
                    {
                        (bool success, bytes memory resultData) = target.delegatecall(data);
                        if (!success ||
                            resultData.length != 32 ||
                            abi.decode(resultData, (bytes4)) != MIGRATE_SUCCESS)
                        {
                            LibOwnableRichErrors.MigrateCallFailedError(target, resultData).rrevert();
                        }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "../fixins/FixinCommon.sol";
                import "../storage/LibProxyStorage.sol";
                import "../storage/LibSimpleFunctionRegistryStorage.sol";
                import "../errors/LibSimpleFunctionRegistryRichErrors.sol";
                import "../migrations/LibBootstrap.sol";
                import "./IFeature.sol";
                import "./ISimpleFunctionRegistry.sol";
                /// @dev Basic registry management features.
                contract SimpleFunctionRegistry is
                    IFeature,
                    ISimpleFunctionRegistry,
                    FixinCommon
                {
                    // solhint-disable
                    /// @dev Name of this feature.
                    string public constant override FEATURE_NAME = "SimpleFunctionRegistry";
                    /// @dev Version of this feature.
                    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
                    /// @dev The deployed address of this contract.
                    address private immutable _implementation;
                    // solhint-enable
                    using LibRichErrorsV06 for bytes;
                    constructor() public {
                        _implementation = address(this);
                    }
                    /// @dev Initializes this feature, registering its own functions.
                    /// @return success Magic bytes if successful.
                    function bootstrap()
                        external
                        returns (bytes4 success)
                    {
                        // Register the registration functions (inception vibes).
                        _extend(this.extend.selector, _implementation);
                        _extend(this._extendSelf.selector, _implementation);
                        // Register the rollback function.
                        _extend(this.rollback.selector, _implementation);
                        // Register getters.
                        _extend(this.getRollbackLength.selector, _implementation);
                        _extend(this.getRollbackEntryAtIndex.selector, _implementation);
                        return LibBootstrap.BOOTSTRAP_SUCCESS;
                    }
                    /// @dev Roll back to a prior implementation of a function.
                    ///      Only directly callable by an authority.
                    /// @param selector The function selector.
                    /// @param targetImpl The address of an older implementation of the function.
                    function rollback(bytes4 selector, address targetImpl)
                        external
                        override
                        onlyOwner
                    {
                        (
                            LibSimpleFunctionRegistryStorage.Storage storage stor,
                            LibProxyStorage.Storage storage proxyStor
                        ) = _getStorages();
                        address currentImpl = proxyStor.impls[selector];
                        if (currentImpl == targetImpl) {
                            // Do nothing if already at targetImpl.
                            return;
                        }
                        // Walk history backwards until we find the target implementation.
                        address[] storage history = stor.implHistory[selector];
                        uint256 i = history.length;
                        for (; i > 0; --i) {
                            address impl = history[i - 1];
                            history.pop();
                            if (impl == targetImpl) {
                                break;
                            }
                        }
                        if (i == 0) {
                            LibSimpleFunctionRegistryRichErrors.NotInRollbackHistoryError(
                                selector,
                                targetImpl
                            ).rrevert();
                        }
                        proxyStor.impls[selector] = targetImpl;
                        emit ProxyFunctionUpdated(selector, currentImpl, targetImpl);
                    }
                    /// @dev Register or replace a function.
                    ///      Only directly callable by an authority.
                    /// @param selector The function selector.
                    /// @param impl The implementation contract for the function.
                    function extend(bytes4 selector, address impl)
                        external
                        override
                        onlyOwner
                    {
                        _extend(selector, impl);
                    }
                    /// @dev Register or replace a function.
                    ///      Only callable from within.
                    ///      This function is only used during the bootstrap process and
                    ///      should be deregistered by the deployer after bootstrapping is
                    ///      complete.
                    /// @param selector The function selector.
                    /// @param impl The implementation contract for the function.
                    function _extendSelf(bytes4 selector, address impl)
                        external
                        onlySelf
                    {
                        _extend(selector, impl);
                    }
                    /// @dev Retrieve the length of the rollback history for a function.
                    /// @param selector The function selector.
                    /// @return rollbackLength The number of items in the rollback history for
                    ///         the function.
                    function getRollbackLength(bytes4 selector)
                        external
                        override
                        view
                        returns (uint256 rollbackLength)
                    {
                        return LibSimpleFunctionRegistryStorage.getStorage().implHistory[selector].length;
                    }
                    /// @dev Retrieve an entry in the rollback history for a function.
                    /// @param selector The function selector.
                    /// @param idx The index in the rollback history.
                    /// @return impl An implementation address for the function at
                    ///         index `idx`.
                    function getRollbackEntryAtIndex(bytes4 selector, uint256 idx)
                        external
                        override
                        view
                        returns (address impl)
                    {
                        return LibSimpleFunctionRegistryStorage.getStorage().implHistory[selector][idx];
                    }
                    /// @dev Register or replace a function.
                    /// @param selector The function selector.
                    /// @param impl The implementation contract for the function.
                    function _extend(bytes4 selector, address impl)
                        private
                    {
                        (
                            LibSimpleFunctionRegistryStorage.Storage storage stor,
                            LibProxyStorage.Storage storage proxyStor
                        ) = _getStorages();
                        address oldImpl = proxyStor.impls[selector];
                        address[] storage history = stor.implHistory[selector];
                        history.push(oldImpl);
                        proxyStor.impls[selector] = impl;
                        emit ProxyFunctionUpdated(selector, oldImpl, impl);
                    }
                    /// @dev Get the storage buckets for this feature and the proxy.
                    /// @return stor Storage bucket for this feature.
                    /// @return proxyStor age bucket for the proxy.
                    function _getStorages()
                        private
                        pure
                        returns (
                            LibSimpleFunctionRegistryStorage.Storage storage stor,
                            LibProxyStorage.Storage storage proxyStor
                        )
                    {
                        return (
                            LibSimpleFunctionRegistryStorage.getStorage(),
                            LibProxyStorage.getStorage()
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "./LibStorage.sol";
                /// @dev Storage helpers for the `SimpleFunctionRegistry` feature.
                library LibSimpleFunctionRegistryStorage {
                    /// @dev Storage bucket for this feature.
                    struct Storage {
                        // Mapping of function selector -> implementation history.
                        mapping(bytes4 => address[]) implHistory;
                    }
                    /// @dev Get the storage bucket for this contract.
                    function getStorage() internal pure returns (Storage storage stor) {
                        uint256 storageSlot = LibStorage.getStorageSlot(
                            LibStorage.StorageId.SimpleFunctionRegistry
                        );
                        // Dip into assembly to change the slot pointed to by the local
                        // variable `stor`.
                        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                        assembly { stor_slot := storageSlot }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
                import "../errors/LibSpenderRichErrors.sol";
                import "../fixins/FixinCommon.sol";
                import "../migrations/LibMigrate.sol";
                import "../external/IAllowanceTarget.sol";
                import "../storage/LibTokenSpenderStorage.sol";
                import "./ITokenSpender.sol";
                import "./IFeature.sol";
                import "./ISimpleFunctionRegistry.sol";
                /// @dev Feature that allows spending token allowances.
                contract TokenSpender is
                    IFeature,
                    ITokenSpender,
                    FixinCommon
                {
                    // solhint-disable
                    /// @dev Name of this feature.
                    string public constant override FEATURE_NAME = "TokenSpender";
                    /// @dev Version of this feature.
                    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
                    /// @dev The implementation address of this feature.
                    address private immutable _implementation;
                    // solhint-enable
                    using LibRichErrorsV06 for bytes;
                    constructor() public {
                        _implementation = address(this);
                    }
                    /// @dev Initialize and register this feature. Should be delegatecalled
                    ///      into during a `Migrate.migrate()`.
                    /// @param allowanceTarget An `allowanceTarget` instance, configured to have
                    ///        the ZeroeEx contract as an authority.
                    /// @return success `MIGRATE_SUCCESS` on success.
                    function migrate(IAllowanceTarget allowanceTarget) external returns (bytes4 success) {
                        LibTokenSpenderStorage.getStorage().allowanceTarget = allowanceTarget;
                        ISimpleFunctionRegistry(address(this))
                            .extend(this.getAllowanceTarget.selector, _implementation);
                        ISimpleFunctionRegistry(address(this))
                            .extend(this._spendERC20Tokens.selector, _implementation);
                        ISimpleFunctionRegistry(address(this))
                            .extend(this.getSpendableERC20BalanceOf.selector, _implementation);
                        return LibMigrate.MIGRATE_SUCCESS;
                    }
                    /// @dev Transfers ERC20 tokens from `owner` to `to`. Only callable from within.
                    /// @param token The token to spend.
                    /// @param owner The owner of the tokens.
                    /// @param to The recipient of the tokens.
                    /// @param amount The amount of `token` to transfer.
                    function _spendERC20Tokens(
                        IERC20TokenV06 token,
                        address owner,
                        address to,
                        uint256 amount
                    )
                        external
                        override
                        onlySelf
                    {
                        IAllowanceTarget spender = LibTokenSpenderStorage.getStorage().allowanceTarget;
                        // Have the allowance target execute an ERC20 `transferFrom()`.
                        (bool didSucceed, bytes memory resultData) = address(spender).call(
                            abi.encodeWithSelector(
                                IAllowanceTarget.executeCall.selector,
                                address(token),
                                abi.encodeWithSelector(
                                    IERC20TokenV06.transferFrom.selector,
                                    owner,
                                    to,
                                    amount
                                )
                            )
                        );
                        if (didSucceed) {
                            resultData = abi.decode(resultData, (bytes));
                        }
                        if (!didSucceed || !LibERC20TokenV06.isSuccessfulResult(resultData)) {
                            LibSpenderRichErrors.SpenderERC20TransferFromFailedError(
                                address(token),
                                owner,
                                to,
                                amount,
                                resultData
                            ).rrevert();
                        }
                    }
                    /// @dev Gets the maximum amount of an ERC20 token `token` that can be
                    ///      pulled from `owner` by the token spender.
                    /// @param token The token to spend.
                    /// @param owner The owner of the tokens.
                    /// @return amount The amount of tokens that can be pulled.
                    function getSpendableERC20BalanceOf(IERC20TokenV06 token, address owner)
                        external
                        override
                        view
                        returns (uint256 amount)
                    {
                        return LibSafeMathV06.min256(
                            token.allowance(owner, address(LibTokenSpenderStorage.getStorage().allowanceTarget)),
                            token.balanceOf(owner)
                        );
                    }
                    /// @dev Get the address of the allowance target.
                    /// @return target The target of token allowances.
                    function getAllowanceTarget()
                        external
                        override
                        view
                        returns (address target)
                    {
                        return address(LibTokenSpenderStorage.getStorage().allowanceTarget);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "./errors/LibRichErrorsV06.sol";
                import "./errors/LibSafeMathRichErrorsV06.sol";
                library LibSafeMathV06 {
                    function safeMul(uint256 a, uint256 b)
                        internal
                        pure
                        returns (uint256)
                    {
                        if (a == 0) {
                            return 0;
                        }
                        uint256 c = a * b;
                        if (c / a != b) {
                            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                                LibSafeMathRichErrorsV06.BinOpErrorCodes.MULTIPLICATION_OVERFLOW,
                                a,
                                b
                            ));
                        }
                        return c;
                    }
                    function safeDiv(uint256 a, uint256 b)
                        internal
                        pure
                        returns (uint256)
                    {
                        if (b == 0) {
                            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                                LibSafeMathRichErrorsV06.BinOpErrorCodes.DIVISION_BY_ZERO,
                                a,
                                b
                            ));
                        }
                        uint256 c = a / b;
                        return c;
                    }
                    function safeSub(uint256 a, uint256 b)
                        internal
                        pure
                        returns (uint256)
                    {
                        if (b > a) {
                            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                                LibSafeMathRichErrorsV06.BinOpErrorCodes.SUBTRACTION_UNDERFLOW,
                                a,
                                b
                            ));
                        }
                        return a - b;
                    }
                    function safeAdd(uint256 a, uint256 b)
                        internal
                        pure
                        returns (uint256)
                    {
                        uint256 c = a + b;
                        if (c < a) {
                            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                                LibSafeMathRichErrorsV06.BinOpErrorCodes.ADDITION_OVERFLOW,
                                a,
                                b
                            ));
                        }
                        return c;
                    }
                    function max256(uint256 a, uint256 b)
                        internal
                        pure
                        returns (uint256)
                    {
                        return a >= b ? a : b;
                    }
                    function min256(uint256 a, uint256 b)
                        internal
                        pure
                        returns (uint256)
                    {
                        return a < b ? a : b;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibSafeMathRichErrorsV06 {
                    // bytes4(keccak256("Uint256BinOpError(uint8,uint256,uint256)"))
                    bytes4 internal constant UINT256_BINOP_ERROR_SELECTOR =
                        0xe946c1bb;
                    // bytes4(keccak256("Uint256DowncastError(uint8,uint256)"))
                    bytes4 internal constant UINT256_DOWNCAST_ERROR_SELECTOR =
                        0xc996af7b;
                    enum BinOpErrorCodes {
                        ADDITION_OVERFLOW,
                        MULTIPLICATION_OVERFLOW,
                        SUBTRACTION_UNDERFLOW,
                        DIVISION_BY_ZERO
                    }
                    enum DowncastErrorCodes {
                        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT32,
                        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT64,
                        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT96
                    }
                    // solhint-disable func-name-mixedcase
                    function Uint256BinOpError(
                        BinOpErrorCodes errorCode,
                        uint256 a,
                        uint256 b
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            UINT256_BINOP_ERROR_SELECTOR,
                            errorCode,
                            a,
                            b
                        );
                    }
                    function Uint256DowncastError(
                        DowncastErrorCodes errorCode,
                        uint256 a
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            UINT256_DOWNCAST_ERROR_SELECTOR,
                            errorCode,
                            a
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
                import "./IERC20TokenV06.sol";
                library LibERC20TokenV06 {
                    bytes constant private DECIMALS_CALL_DATA = hex"313ce567";
                    /// @dev Calls `IERC20TokenV06(token).approve()`.
                    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
                    /// @param token The address of the token contract.
                    /// @param spender The address that receives an allowance.
                    /// @param allowance The allowance to set.
                    function compatApprove(
                        IERC20TokenV06 token,
                        address spender,
                        uint256 allowance
                    )
                        internal
                    {
                        bytes memory callData = abi.encodeWithSelector(
                            token.approve.selector,
                            spender,
                            allowance
                        );
                        _callWithOptionalBooleanResult(address(token), callData);
                    }
                    /// @dev Calls `IERC20TokenV06(token).approve()` and sets the allowance to the
                    ///      maximum if the current approval is not already >= an amount.
                    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
                    /// @param token The address of the token contract.
                    /// @param spender The address that receives an allowance.
                    /// @param amount The minimum allowance needed.
                    function approveIfBelow(
                        IERC20TokenV06 token,
                        address spender,
                        uint256 amount
                    )
                        internal
                    {
                        if (token.allowance(address(this), spender) < amount) {
                            compatApprove(token, spender, uint256(-1));
                        }
                    }
                    /// @dev Calls `IERC20TokenV06(token).transfer()`.
                    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
                    /// @param token The address of the token contract.
                    /// @param to The address that receives the tokens
                    /// @param amount Number of tokens to transfer.
                    function compatTransfer(
                        IERC20TokenV06 token,
                        address to,
                        uint256 amount
                    )
                        internal
                    {
                        bytes memory callData = abi.encodeWithSelector(
                            token.transfer.selector,
                            to,
                            amount
                        );
                        _callWithOptionalBooleanResult(address(token), callData);
                    }
                    /// @dev Calls `IERC20TokenV06(token).transferFrom()`.
                    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
                    /// @param token The address of the token contract.
                    /// @param from The owner of the tokens.
                    /// @param to The address that receives the tokens
                    /// @param amount Number of tokens to transfer.
                    function compatTransferFrom(
                        IERC20TokenV06 token,
                        address from,
                        address to,
                        uint256 amount
                    )
                        internal
                    {
                        bytes memory callData = abi.encodeWithSelector(
                            token.transferFrom.selector,
                            from,
                            to,
                            amount
                        );
                        _callWithOptionalBooleanResult(address(token), callData);
                    }
                    /// @dev Retrieves the number of decimals for a token.
                    ///      Returns `18` if the call reverts.
                    /// @param token The address of the token contract.
                    /// @return tokenDecimals The number of decimals places for the token.
                    function compatDecimals(IERC20TokenV06 token)
                        internal
                        view
                        returns (uint8 tokenDecimals)
                    {
                        tokenDecimals = 18;
                        (bool didSucceed, bytes memory resultData) = address(token).staticcall(DECIMALS_CALL_DATA);
                        if (didSucceed && resultData.length == 32) {
                            tokenDecimals = uint8(LibBytesV06.readUint256(resultData, 0));
                        }
                    }
                    /// @dev Retrieves the allowance for a token, owner, and spender.
                    ///      Returns `0` if the call reverts.
                    /// @param token The address of the token contract.
                    /// @param owner The owner of the tokens.
                    /// @param spender The address the spender.
                    /// @return allowance_ The allowance for a token, owner, and spender.
                    function compatAllowance(IERC20TokenV06 token, address owner, address spender)
                        internal
                        view
                        returns (uint256 allowance_)
                    {
                        (bool didSucceed, bytes memory resultData) = address(token).staticcall(
                            abi.encodeWithSelector(
                                token.allowance.selector,
                                owner,
                                spender
                            )
                        );
                        if (didSucceed && resultData.length == 32) {
                            allowance_ = LibBytesV06.readUint256(resultData, 0);
                        }
                    }
                    /// @dev Retrieves the balance for a token owner.
                    ///      Returns `0` if the call reverts.
                    /// @param token The address of the token contract.
                    /// @param owner The owner of the tokens.
                    /// @return balance The token balance of an owner.
                    function compatBalanceOf(IERC20TokenV06 token, address owner)
                        internal
                        view
                        returns (uint256 balance)
                    {
                        (bool didSucceed, bytes memory resultData) = address(token).staticcall(
                            abi.encodeWithSelector(
                                token.balanceOf.selector,
                                owner
                            )
                        );
                        if (didSucceed && resultData.length == 32) {
                            balance = LibBytesV06.readUint256(resultData, 0);
                        }
                    }
                    /// @dev Check if the data returned by a non-static call to an ERC20 token
                    ///      is a successful result. Supported functions are `transfer()`,
                    ///      `transferFrom()`, and `approve()`.
                    /// @param resultData The raw data returned by a non-static call to the ERC20 token.
                    /// @return isSuccessful Whether the result data indicates success.
                    function isSuccessfulResult(bytes memory resultData)
                        internal
                        pure
                        returns (bool isSuccessful)
                    {
                        if (resultData.length == 0) {
                            return true;
                        }
                        if (resultData.length == 32) {
                            uint256 result = LibBytesV06.readUint256(resultData, 0);
                            if (result == 1) {
                                return true;
                            }
                        }
                    }
                    /// @dev Executes a call on address `target` with calldata `callData`
                    ///      and asserts that either nothing was returned or a single boolean
                    ///      was returned equal to `true`.
                    /// @param target The call target.
                    /// @param callData The abi-encoded call data.
                    function _callWithOptionalBooleanResult(
                        address target,
                        bytes memory callData
                    )
                        private
                    {
                        (bool didSucceed, bytes memory resultData) = target.call(callData);
                        if (didSucceed && isSuccessfulResult(resultData)) {
                            return;
                        }
                        LibRichErrorsV06.rrevert(resultData);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "./LibStorage.sol";
                import "../external/IAllowanceTarget.sol";
                /// @dev Storage helpers for the `TokenSpender` feature.
                library LibTokenSpenderStorage {
                    /// @dev Storage bucket for this feature.
                    struct Storage {
                        // Allowance target contract.
                        IAllowanceTarget allowanceTarget;
                    }
                    /// @dev Get the storage bucket for this contract.
                    function getStorage() internal pure returns (Storage storage stor) {
                        uint256 storageSlot = LibStorage.getStorageSlot(
                            LibStorage.StorageId.TokenSpender
                        );
                        // Dip into assembly to change the slot pointed to by the local
                        // variable `stor`.
                        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                        assembly { stor_slot := storageSlot }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
                import "../errors/LibTransformERC20RichErrors.sol";
                import "../fixins/FixinCommon.sol";
                import "../migrations/LibMigrate.sol";
                import "../external/IFlashWallet.sol";
                import "../external/FlashWallet.sol";
                import "../storage/LibTransformERC20Storage.sol";
                import "../transformers/IERC20Transformer.sol";
                import "../transformers/LibERC20Transformer.sol";
                import "./ITransformERC20.sol";
                import "./ITokenSpender.sol";
                import "./IFeature.sol";
                import "./ISimpleFunctionRegistry.sol";
                /// @dev Feature to composably transform between ERC20 tokens.
                contract TransformERC20 is
                    IFeature,
                    ITransformERC20,
                    FixinCommon
                {
                    /// @dev Stack vars for `_transformERC20Private()`.
                    struct TransformERC20PrivateState {
                        IFlashWallet wallet;
                        address transformerDeployer;
                        uint256 takerOutputTokenBalanceBefore;
                        uint256 takerOutputTokenBalanceAfter;
                    }
                    // solhint-disable
                    /// @dev Name of this feature.
                    string public constant override FEATURE_NAME = "TransformERC20";
                    /// @dev Version of this feature.
                    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
                    /// @dev The implementation address of this feature.
                    address private immutable _implementation;
                    // solhint-enable
                    using LibSafeMathV06 for uint256;
                    using LibRichErrorsV06 for bytes;
                    constructor() public {
                        _implementation = address(this);
                    }
                    /// @dev Initialize and register this feature.
                    ///      Should be delegatecalled by `Migrate.migrate()`.
                    /// @param transformerDeployer The trusted deployer for transformers.
                    /// @return success `LibMigrate.SUCCESS` on success.
                    function migrate(address transformerDeployer) external returns (bytes4 success) {
                        ISimpleFunctionRegistry(address(this))
                            .extend(this.getTransformerDeployer.selector, _implementation);
                        ISimpleFunctionRegistry(address(this))
                            .extend(this.createTransformWallet.selector, _implementation);
                        ISimpleFunctionRegistry(address(this))
                            .extend(this.getTransformWallet.selector, _implementation);
                        ISimpleFunctionRegistry(address(this))
                            .extend(this.setTransformerDeployer.selector, _implementation);
                        ISimpleFunctionRegistry(address(this))
                            .extend(this.transformERC20.selector, _implementation);
                        ISimpleFunctionRegistry(address(this))
                            .extend(this._transformERC20.selector, _implementation);
                        createTransformWallet();
                        LibTransformERC20Storage.getStorage().transformerDeployer = transformerDeployer;
                        return LibMigrate.MIGRATE_SUCCESS;
                    }
                    /// @dev Replace the allowed deployer for transformers.
                    ///      Only callable by the owner.
                    /// @param transformerDeployer The address of the trusted deployer for transformers.
                    function setTransformerDeployer(address transformerDeployer)
                        external
                        override
                        onlyOwner
                    {
                        LibTransformERC20Storage.getStorage().transformerDeployer = transformerDeployer;
                        emit TransformerDeployerUpdated(transformerDeployer);
                    }
                    /// @dev Return the allowed deployer for transformers.
                    /// @return deployer The transform deployer address.
                    function getTransformerDeployer()
                        public
                        override
                        view
                        returns (address deployer)
                    {
                        return LibTransformERC20Storage.getStorage().transformerDeployer;
                    }
                    /// @dev Deploy a new wallet instance and replace the current one with it.
                    ///      Useful if we somehow break the current wallet instance.
                    ///      Anyone can call this.
                    /// @return wallet The new wallet instance.
                    function createTransformWallet()
                        public
                        override
                        returns (IFlashWallet wallet)
                    {
                        wallet = new FlashWallet();
                        LibTransformERC20Storage.getStorage().wallet = wallet;
                    }
                    /// @dev Executes a series of transformations to convert an ERC20 `inputToken`
                    ///      to an ERC20 `outputToken`.
                    /// @param inputToken The token being provided by the sender.
                    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
                    /// @param outputToken The token to be acquired by the sender.
                    ///        `0xeee...` implies ETH.
                    /// @param inputTokenAmount The amount of `inputToken` to take from the sender.
                    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
                    ///        will be solt.
                    /// @param minOutputTokenAmount The minimum amount of `outputToken` the sender
                    ///        must receive for the entire transformation to succeed. If set to zero,
                    ///        the minimum output token transfer will not be asserted.
                    /// @param transformations The transformations to execute on the token balance(s)
                    ///        in sequence.
                    /// @return outputTokenAmount The amount of `outputToken` received by the sender.
                    function transformERC20(
                        IERC20TokenV06 inputToken,
                        IERC20TokenV06 outputToken,
                        uint256 inputTokenAmount,
                        uint256 minOutputTokenAmount,
                        Transformation[] memory transformations
                    )
                        public
                        override
                        payable
                        returns (uint256 outputTokenAmount)
                    {
                        return _transformERC20Private(
                            keccak256(msg.data),
                            msg.sender,
                            inputToken,
                            outputToken,
                            inputTokenAmount,
                            minOutputTokenAmount,
                            transformations
                        );
                    }
                    /// @dev Internal version of `transformERC20()`. Only callable from within.
                    /// @param callDataHash Hash of the ingress calldata.
                    /// @param taker The taker address.
                    /// @param inputToken The token being provided by the taker.
                    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
                    /// @param outputToken The token to be acquired by the taker.
                    ///        `0xeee...` implies ETH.
                    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
                    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
                    ///        will be solt.
                    /// @param minOutputTokenAmount The minimum amount of `outputToken` the taker
                    ///        must receive for the entire transformation to succeed. If set to zero,
                    ///        the minimum output token transfer will not be asserted.
                    /// @param transformations The transformations to execute on the token balance(s)
                    ///        in sequence.
                    /// @return outputTokenAmount The amount of `outputToken` received by the taker.
                    function _transformERC20(
                        bytes32 callDataHash,
                        address payable taker,
                        IERC20TokenV06 inputToken,
                        IERC20TokenV06 outputToken,
                        uint256 inputTokenAmount,
                        uint256 minOutputTokenAmount,
                        Transformation[] memory transformations
                    )
                        public
                        override
                        payable
                        onlySelf
                        returns (uint256 outputTokenAmount)
                    {
                        return _transformERC20Private(
                            callDataHash,
                            taker,
                            inputToken,
                            outputToken,
                            inputTokenAmount,
                            minOutputTokenAmount,
                            transformations
                        );
                    }
                    /// @dev Private version of `transformERC20()`.
                    /// @param callDataHash Hash of the ingress calldata.
                    /// @param taker The taker address.
                    /// @param inputToken The token being provided by the taker.
                    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
                    /// @param outputToken The token to be acquired by the taker.
                    ///        `0xeee...` implies ETH.
                    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
                    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
                    ///        will be solt.
                    /// @param minOutputTokenAmount The minimum amount of `outputToken` the taker
                    ///        must receive for the entire transformation to succeed. If set to zero,
                    ///        the minimum output token transfer will not be asserted.
                    /// @param transformations The transformations to execute on the token balance(s)
                    ///        in sequence.
                    /// @return outputTokenAmount The amount of `outputToken` received by the taker.
                    function _transformERC20Private(
                        bytes32 callDataHash,
                        address payable taker,
                        IERC20TokenV06 inputToken,
                        IERC20TokenV06 outputToken,
                        uint256 inputTokenAmount,
                        uint256 minOutputTokenAmount,
                        Transformation[] memory transformations
                    )
                        private
                        returns (uint256 outputTokenAmount)
                    {
                        // If the input token amount is -1, transform the taker's entire
                        // spendable balance.
                        if (inputTokenAmount == uint256(-1)) {
                            inputTokenAmount = ITokenSpender(address(this))
                                .getSpendableERC20BalanceOf(inputToken, taker);
                        }
                        TransformERC20PrivateState memory state;
                        state.wallet = getTransformWallet();
                        state.transformerDeployer = getTransformerDeployer();
                        // Remember the initial output token balance of the taker.
                        state.takerOutputTokenBalanceBefore =
                            LibERC20Transformer.getTokenBalanceOf(outputToken, taker);
                        // Pull input tokens from the taker to the wallet and transfer attached ETH.
                        _transferInputTokensAndAttachedEth(
                            inputToken,
                            taker,
                            address(state.wallet),
                            inputTokenAmount
                        );
                        // Perform transformations.
                        for (uint256 i = 0; i < transformations.length; ++i) {
                            _executeTransformation(
                                state.wallet,
                                transformations[i],
                                state.transformerDeployer,
                                taker,
                                callDataHash
                            );
                        }
                        // Compute how much output token has been transferred to the taker.
                        state.takerOutputTokenBalanceAfter =
                            LibERC20Transformer.getTokenBalanceOf(outputToken, taker);
                        if (state.takerOutputTokenBalanceAfter > state.takerOutputTokenBalanceBefore) {
                            outputTokenAmount = state.takerOutputTokenBalanceAfter.safeSub(
                                state.takerOutputTokenBalanceBefore
                            );
                        } else if (state.takerOutputTokenBalanceAfter < state.takerOutputTokenBalanceBefore) {
                            LibTransformERC20RichErrors.NegativeTransformERC20OutputError(
                                address(outputToken),
                                state.takerOutputTokenBalanceBefore - state.takerOutputTokenBalanceAfter
                            ).rrevert();
                        }
                        // Ensure enough output token has been sent to the taker.
                        if (outputTokenAmount < minOutputTokenAmount) {
                            LibTransformERC20RichErrors.IncompleteTransformERC20Error(
                                address(outputToken),
                                outputTokenAmount,
                                minOutputTokenAmount
                            ).rrevert();
                        }
                        // Emit an event.
                        emit TransformedERC20(
                            taker,
                            address(inputToken),
                            address(outputToken),
                            inputTokenAmount,
                            outputTokenAmount
                        );
                    }
                    /// @dev Return the current wallet instance that will serve as the execution
                    ///      context for transformations.
                    /// @return wallet The wallet instance.
                    function getTransformWallet()
                        public
                        override
                        view
                        returns (IFlashWallet wallet)
                    {
                        return LibTransformERC20Storage.getStorage().wallet;
                    }
                    /// @dev Transfer input tokens from the taker and any attached ETH to `to`
                    /// @param inputToken The token to pull from the taker.
                    /// @param from The from (taker) address.
                    /// @param to The recipient of tokens and ETH.
                    /// @param amount Amount of `inputToken` tokens to transfer.
                    function _transferInputTokensAndAttachedEth(
                        IERC20TokenV06 inputToken,
                        address from,
                        address payable to,
                        uint256 amount
                    )
                        private
                    {
                        // Transfer any attached ETH.
                        if (msg.value != 0) {
                            to.transfer(msg.value);
                        }
                        // Transfer input tokens.
                        if (!LibERC20Transformer.isTokenETH(inputToken)) {
                            // Token is not ETH, so pull ERC20 tokens.
                            ITokenSpender(address(this))._spendERC20Tokens(
                                inputToken,
                                from,
                                to,
                                amount
                            );
                        } else if (msg.value < amount) {
                             // Token is ETH, so the caller must attach enough ETH to the call.
                            LibTransformERC20RichErrors.InsufficientEthAttachedError(
                                msg.value,
                                amount
                            ).rrevert();
                        }
                    }
                    /// @dev Executs a transformer in the context of `wallet`.
                    /// @param wallet The wallet instance.
                    /// @param transformation The transformation.
                    /// @param transformerDeployer The address of the transformer deployer.
                    /// @param taker The taker address.
                    /// @param callDataHash Hash of the calldata.
                    function _executeTransformation(
                        IFlashWallet wallet,
                        Transformation memory transformation,
                        address transformerDeployer,
                        address payable taker,
                        bytes32 callDataHash
                    )
                        private
                    {
                        // Derive the transformer address from the deployment nonce.
                        address payable transformer = LibERC20Transformer.getDeployedAddress(
                            transformerDeployer,
                            transformation.deploymentNonce
                        );
                        // Call `transformer.transform()` as the wallet.
                        bytes memory resultData = wallet.executeDelegateCall(
                            // The call target.
                            transformer,
                            // Call data.
                            abi.encodeWithSelector(
                                IERC20Transformer.transform.selector,
                                callDataHash,
                                taker,
                                transformation.data
                            )
                        );
                        // Ensure the transformer returned the magic bytes.
                        if (resultData.length != 32 ||
                            abi.decode(resultData, (bytes4)) != LibERC20Transformer.TRANSFORMER_SUCCESS
                        ) {
                            LibTransformERC20RichErrors.TransformerFailedError(
                                transformer,
                                transformation.data,
                                resultData
                            ).rrevert();
                        }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "./LibStorage.sol";
                import "../external/IFlashWallet.sol";
                /// @dev Storage helpers for the `TokenSpender` feature.
                library LibTransformERC20Storage {
                    /// @dev Storage bucket for this feature.
                    struct Storage {
                        // The current wallet instance.
                        IFlashWallet wallet;
                        // The transformer deployer address.
                        address transformerDeployer;
                    }
                    /// @dev Get the storage bucket for this contract.
                    function getStorage() internal pure returns (Storage storage stor) {
                        uint256 storageSlot = LibStorage.getStorageSlot(
                            LibStorage.StorageId.TransformERC20
                        );
                        // Dip into assembly to change the slot pointed to by the local
                        // variable `stor`.
                        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                        assembly { stor_slot := storageSlot }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
                library LibERC20Transformer {
                    using LibERC20TokenV06 for IERC20TokenV06;
                    /// @dev ETH pseudo-token address.
                    address constant internal ETH_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
                    /// @dev Return value indicating success in `IERC20Transformer.transform()`.
                    ///      This is just `keccak256('TRANSFORMER_SUCCESS')`.
                    bytes4 constant internal TRANSFORMER_SUCCESS = 0x13c9929e;
                    /// @dev Transfer ERC20 tokens and ETH.
                    /// @param token An ERC20 or the ETH pseudo-token address (`ETH_TOKEN_ADDRESS`).
                    /// @param to The recipient.
                    /// @param amount The transfer amount.
                    function transformerTransfer(
                        IERC20TokenV06 token,
                        address payable to,
                        uint256 amount
                    )
                        internal
                    {
                        if (isTokenETH(token)) {
                            to.transfer(amount);
                        } else {
                            token.compatTransfer(to, amount);
                        }
                    }
                    /// @dev Check if a token is the ETH pseudo-token.
                    /// @param token The token to check.
                    /// @return isETH `true` if the token is the ETH pseudo-token.
                    function isTokenETH(IERC20TokenV06 token)
                        internal
                        pure
                        returns (bool isETH)
                    {
                        return address(token) == ETH_TOKEN_ADDRESS;
                    }
                    /// @dev Check the balance of an ERC20 token or ETH.
                    /// @param token An ERC20 or the ETH pseudo-token address (`ETH_TOKEN_ADDRESS`).
                    /// @param owner Holder of the tokens.
                    /// @return tokenBalance The balance of `owner`.
                    function getTokenBalanceOf(IERC20TokenV06 token, address owner)
                        internal
                        view
                        returns (uint256 tokenBalance)
                    {
                        if (isTokenETH(token)) {
                            return owner.balance;
                        }
                        return token.balanceOf(owner);
                    }
                    /// @dev RLP-encode a 32-bit or less account nonce.
                    /// @param nonce A positive integer in the range 0 <= nonce < 2^32.
                    /// @return rlpNonce The RLP encoding.
                    function rlpEncodeNonce(uint32 nonce)
                        internal
                        pure
                        returns (bytes memory rlpNonce)
                    {
                        // See https://github.com/ethereum/wiki/wiki/RLP for RLP encoding rules.
                        if (nonce == 0) {
                            rlpNonce = new bytes(1);
                            rlpNonce[0] = 0x80;
                        } else if (nonce < 0x80) {
                            rlpNonce = new bytes(1);
                            rlpNonce[0] = byte(uint8(nonce));
                        } else if (nonce <= 0xFF) {
                            rlpNonce = new bytes(2);
                            rlpNonce[0] = 0x81;
                            rlpNonce[1] = byte(uint8(nonce));
                        } else if (nonce <= 0xFFFF) {
                            rlpNonce = new bytes(3);
                            rlpNonce[0] = 0x82;
                            rlpNonce[1] = byte(uint8((nonce & 0xFF00) >> 8));
                            rlpNonce[2] = byte(uint8(nonce));
                        } else if (nonce <= 0xFFFFFF) {
                            rlpNonce = new bytes(4);
                            rlpNonce[0] = 0x83;
                            rlpNonce[1] = byte(uint8((nonce & 0xFF0000) >> 16));
                            rlpNonce[2] = byte(uint8((nonce & 0xFF00) >> 8));
                            rlpNonce[3] = byte(uint8(nonce));
                        } else {
                            rlpNonce = new bytes(5);
                            rlpNonce[0] = 0x84;
                            rlpNonce[1] = byte(uint8((nonce & 0xFF000000) >> 24));
                            rlpNonce[2] = byte(uint8((nonce & 0xFF0000) >> 16));
                            rlpNonce[3] = byte(uint8((nonce & 0xFF00) >> 8));
                            rlpNonce[4] = byte(uint8(nonce));
                        }
                    }
                    /// @dev Compute the expected deployment address by `deployer` at
                    ///      the nonce given by `deploymentNonce`.
                    /// @param deployer The address of the deployer.
                    /// @param deploymentNonce The nonce that the deployer had when deploying
                    ///        a contract.
                    /// @return deploymentAddress The deployment address.
                    function getDeployedAddress(address deployer, uint32 deploymentNonce)
                        internal
                        pure
                        returns (address payable deploymentAddress)
                    {
                        // The address of if a deployed contract is the lower 20 bytes of the
                        // hash of the RLP-encoded deployer's account address + account nonce.
                        // See: https://ethereum.stackexchange.com/questions/760/how-is-the-address-of-an-ethereum-contract-computed
                        bytes memory rlpNonce = rlpEncodeNonce(deploymentNonce);
                        return address(uint160(uint256(keccak256(abi.encodePacked(
                            byte(uint8(0xC0 + 21 + rlpNonce.length)),
                            byte(uint8(0x80 + 20)),
                            deployer,
                            rlpNonce
                        )))));
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../ZeroEx.sol";
                import "../features/IOwnable.sol";
                import "../features/TokenSpender.sol";
                import "../features/TransformERC20.sol";
                import "../external/AllowanceTarget.sol";
                import "./InitialMigration.sol";
                /// @dev A contract for deploying and configuring the full ZeroEx contract.
                contract FullMigration {
                    // solhint-disable no-empty-blocks,indent
                    /// @dev Features to add the the proxy contract.
                    struct Features {
                        SimpleFunctionRegistry registry;
                        Ownable ownable;
                        TokenSpender tokenSpender;
                        TransformERC20 transformERC20;
                    }
                    /// @dev Parameters needed to initialize features.
                    struct MigrateOpts {
                        address transformerDeployer;
                    }
                    /// @dev The allowed caller of `deploy()`.
                    address public immutable deployer;
                    /// @dev The initial migration contract.
                    InitialMigration private _initialMigration;
                    /// @dev Instantiate this contract and set the allowed caller of `deploy()`
                    ///      to `deployer`.
                    /// @param deployer_ The allowed caller of `deploy()`.
                    constructor(address payable deployer_)
                        public
                    {
                        deployer = deployer_;
                        // Create an initial migration contract with this contract set to the
                        // allowed deployer.
                        _initialMigration = new InitialMigration(address(this));
                    }
                    /// @dev Deploy the `ZeroEx` contract with the full feature set,
                    ///      transfer ownership to `owner`, then self-destruct.
                    /// @param owner The owner of the contract.
                    /// @param features Features to add to the proxy.
                    /// @return zeroEx The deployed and configured `ZeroEx` contract.
                    /// @param migrateOpts Parameters needed to initialize features.
                    function deploy(
                        address payable owner,
                        Features memory features,
                        MigrateOpts memory migrateOpts
                    )
                        public
                        returns (ZeroEx zeroEx)
                    {
                        require(msg.sender == deployer, "FullMigration/INVALID_SENDER");
                        // Perform the initial migration with the owner set to this contract.
                        zeroEx = _initialMigration.deploy(
                            address(uint160(address(this))),
                            InitialMigration.BootstrapFeatures({
                                registry: features.registry,
                                ownable: features.ownable
                            })
                        );
                        // Add features.
                        _addFeatures(zeroEx, owner, features, migrateOpts);
                        // Transfer ownership to the real owner.
                        IOwnable(address(zeroEx)).transferOwnership(owner);
                        // Self-destruct.
                        this.die(owner);
                    }
                    /// @dev Destroy this contract. Only callable from ourselves (from `deploy()`).
                    /// @param ethRecipient Receiver of any ETH in this contract.
                    function die(address payable ethRecipient)
                        external
                        virtual
                    {
                        require(msg.sender == address(this), "FullMigration/INVALID_SENDER");
                        // This contract should not hold any funds but we send
                        // them to the ethRecipient just in case.
                        selfdestruct(ethRecipient);
                    }
                    /// @dev Deploy and register features to the ZeroEx contract.
                    /// @param zeroEx The bootstrapped ZeroEx contract.
                    /// @param owner The ultimate owner of the ZeroEx contract.
                    /// @param features Features to add to the proxy.
                    /// @param migrateOpts Parameters needed to initialize features.
                    function _addFeatures(
                        ZeroEx zeroEx,
                        address owner,
                        Features memory features,
                        MigrateOpts memory migrateOpts
                    )
                        private
                    {
                        IOwnable ownable = IOwnable(address(zeroEx));
                        // TokenSpender
                        {
                            // Create the allowance target.
                            AllowanceTarget allowanceTarget = new AllowanceTarget();
                            // Let the ZeroEx contract use the allowance target.
                            allowanceTarget.addAuthorizedAddress(address(zeroEx));
                            // Transfer ownership of the allowance target to the (real) owner.
                            allowanceTarget.transferOwnership(owner);
                            // Register the feature.
                            ownable.migrate(
                                address(features.tokenSpender),
                                abi.encodeWithSelector(
                                    TokenSpender.migrate.selector,
                                    allowanceTarget
                                ),
                                address(this)
                            );
                        }
                        // TransformERC20
                        {
                            // Register the feature.
                            ownable.migrate(
                                address(features.transformERC20),
                                abi.encodeWithSelector(
                                    TransformERC20.migrate.selector,
                                    migrateOpts.transformerDeployer
                                ),
                                address(this)
                            );
                        }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../ZeroEx.sol";
                import "../features/IBootstrap.sol";
                import "../features/SimpleFunctionRegistry.sol";
                import "../features/Ownable.sol";
                import "./LibBootstrap.sol";
                /// @dev A contract for deploying and configuring a minimal ZeroEx contract.
                contract InitialMigration {
                    /// @dev Features to bootstrap into the the proxy contract.
                    struct BootstrapFeatures {
                        SimpleFunctionRegistry registry;
                        Ownable ownable;
                    }
                    /// @dev The allowed caller of `deploy()`. In production, this would be
                    ///      the governor.
                    address public immutable deployer;
                    /// @dev The real address of this contract.
                    address private immutable _implementation;
                    /// @dev Instantiate this contract and set the allowed caller of `deploy()`
                    ///      to `deployer_`.
                    /// @param deployer_ The allowed caller of `deploy()`.
                    constructor(address deployer_) public {
                        deployer = deployer_;
                        _implementation = address(this);
                    }
                    /// @dev Deploy the `ZeroEx` contract with the minimum feature set,
                    ///      transfers ownership to `owner`, then self-destructs.
                    ///      Only callable by `deployer` set in the contstructor.
                    /// @param owner The owner of the contract.
                    /// @param features Features to bootstrap into the proxy.
                    /// @return zeroEx The deployed and configured `ZeroEx` contract.
                    function deploy(address payable owner, BootstrapFeatures memory features)
                        public
                        virtual
                        returns (ZeroEx zeroEx)
                    {
                        // Must be called by the allowed deployer.
                        require(msg.sender == deployer, "InitialMigration/INVALID_SENDER");
                        // Deploy the ZeroEx contract, setting ourselves as the bootstrapper.
                        zeroEx = new ZeroEx();
                        // Bootstrap the initial feature set.
                        IBootstrap(address(zeroEx)).bootstrap(
                            address(this),
                            abi.encodeWithSelector(this.bootstrap.selector, owner, features)
                        );
                        // Self-destruct. This contract should not hold any funds but we send
                        // them to the owner just in case.
                        this.die(owner);
                    }
                    /// @dev Sets up the initial state of the `ZeroEx` contract.
                    ///      The `ZeroEx` contract will delegatecall into this function.
                    /// @param owner The new owner of the ZeroEx contract.
                    /// @param features Features to bootstrap into the proxy.
                    /// @return success Magic bytes if successful.
                    function bootstrap(address owner, BootstrapFeatures memory features)
                        public
                        virtual
                        returns (bytes4 success)
                    {
                        // Deploy and migrate the initial features.
                        // Order matters here.
                        // Initialize Registry.
                        LibBootstrap.delegatecallBootstrapFunction(
                            address(features.registry),
                            abi.encodeWithSelector(
                                SimpleFunctionRegistry.bootstrap.selector
                            )
                        );
                        // Initialize Ownable.
                        LibBootstrap.delegatecallBootstrapFunction(
                            address(features.ownable),
                            abi.encodeWithSelector(
                                Ownable.bootstrap.selector
                            )
                        );
                        // De-register `SimpleFunctionRegistry._extendSelf`.
                        SimpleFunctionRegistry(address(this)).rollback(
                            SimpleFunctionRegistry._extendSelf.selector,
                            address(0)
                        );
                        // Transfer ownership to the real owner.
                        Ownable(address(this)).transferOwnership(owner);
                        success = LibBootstrap.BOOTSTRAP_SUCCESS;
                    }
                    /// @dev Self-destructs this contract. Only callable by this contract.
                    /// @param ethRecipient Who to transfer outstanding ETH to.
                    function die(address payable ethRecipient) public virtual {
                        require(msg.sender == _implementation, "InitialMigration/INVALID_SENDER");
                        selfdestruct(ethRecipient);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
                import "../errors/LibTransformERC20RichErrors.sol";
                import "./Transformer.sol";
                import "./LibERC20Transformer.sol";
                /// @dev A transformer that transfers tokens to arbitrary addresses.
                contract AffiliateFeeTransformer is
                    Transformer
                {
                    // solhint-disable no-empty-blocks
                    using LibRichErrorsV06 for bytes;
                    using LibSafeMathV06 for uint256;
                    using LibERC20Transformer for IERC20TokenV06;
                    /// @dev Information for a single fee.
                    struct TokenFee {
                        // The token to transfer to `recipient`.
                        IERC20TokenV06 token;
                        // Amount of each `token` to transfer to `recipient`.
                        // If `amount == uint256(-1)`, the entire balance of `token` will be
                        // transferred.
                        uint256 amount;
                        // Recipient of `token`.
                        address payable recipient;
                    }
                    uint256 private constant MAX_UINT256 = uint256(-1);
                    /// @dev Create this contract.
                    constructor()
                        public
                        Transformer()
                    {}
                    /// @dev Transfers tokens to recipients.
                    /// @param data ABI-encoded `TokenFee[]`, indicating which tokens to transfer.
                    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
                    function transform(
                        bytes32, // callDataHash,
                        address payable, // taker,
                        bytes calldata data
                    )
                        external
                        override
                        returns (bytes4 success)
                    {
                        TokenFee[] memory fees = abi.decode(data, (TokenFee[]));
                        // Transfer tokens to recipients.
                        for (uint256 i = 0; i < fees.length; ++i) {
                            uint256 amount = fees[i].amount;
                            if (amount == MAX_UINT256) {
                                amount = LibERC20Transformer.getTokenBalanceOf(fees[i].token, address(this));
                            }
                            if (amount != 0) {
                                fees[i].token.transformerTransfer(fees[i].recipient, amount);
                            }
                        }
                        return LibERC20Transformer.TRANSFORMER_SUCCESS;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "../errors/LibTransformERC20RichErrors.sol";
                import "./IERC20Transformer.sol";
                /// @dev Abstract base class for transformers.
                abstract contract Transformer is
                    IERC20Transformer
                {
                    using LibRichErrorsV06 for bytes;
                    /// @dev The address of the deployer.
                    address public immutable deployer;
                    /// @dev The original address of this contract.
                    address private immutable _implementation;
                    /// @dev Create this contract.
                    constructor() public {
                        deployer = msg.sender;
                        _implementation = address(this);
                    }
                    /// @dev Destruct this contract. Only callable by the deployer and will not
                    ///      succeed in the context of a delegatecall (from another contract).
                    /// @param ethRecipient The recipient of ETH held in this contract.
                    function die(address payable ethRecipient)
                        external
                        virtual
                    {
                        // Only the deployer can call this.
                        if (msg.sender != deployer) {
                            LibTransformERC20RichErrors
                                .OnlyCallableByDeployerError(msg.sender, deployer)
                                .rrevert();
                        }
                        // Must be executing our own context.
                        if (address(this) != _implementation) {
                            LibTransformERC20RichErrors
                                .InvalidExecutionContextError(address(this), _implementation)
                                .rrevert();
                        }
                        selfdestruct(ethRecipient);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
                import "../errors/LibTransformERC20RichErrors.sol";
                import "../vendor/v3/IExchange.sol";
                import "./Transformer.sol";
                import "./LibERC20Transformer.sol";
                /// @dev A transformer that fills an ERC20 market sell/buy quote.
                contract FillQuoteTransformer is
                    Transformer
                {
                    using LibERC20TokenV06 for IERC20TokenV06;
                    using LibERC20Transformer for IERC20TokenV06;
                    using LibSafeMathV06 for uint256;
                    using LibRichErrorsV06 for bytes;
                    /// @dev Whether we are performing a market sell or buy.
                    enum Side {
                        Sell,
                        Buy
                    }
                    /// @dev Transform data to ABI-encode and pass into `transform()`.
                    struct TransformData {
                        // Whether we aer performing a market sell or buy.
                        Side side;
                        // The token being sold.
                        // This should be an actual token, not the ETH pseudo-token.
                        IERC20TokenV06 sellToken;
                        // The token being bought.
                        // This should be an actual token, not the ETH pseudo-token.
                        IERC20TokenV06 buyToken;
                        // The orders to fill.
                        IExchange.Order[] orders;
                        // Signatures for each respective order in `orders`.
                        bytes[] signatures;
                        // Maximum fill amount for each order. This may be shorter than the
                        // number of orders, where missing entries will be treated as `uint256(-1)`.
                        // For sells, this will be the maximum sell amount (taker asset).
                        // For buys, this will be the maximum buy amount (maker asset).
                        uint256[] maxOrderFillAmounts;
                        // Amount of `sellToken` to sell or `buyToken` to buy.
                        // For sells, this may be `uint256(-1)` to sell the entire balance of
                        // `sellToken`.
                        uint256 fillAmount;
                    }
                    /// @dev Results of a call to `_fillOrder()`.
                    struct FillOrderResults {
                        // The amount of taker tokens sold, according to balance checks.
                        uint256 takerTokenSoldAmount;
                        // The amount of maker tokens sold, according to balance checks.
                        uint256 makerTokenBoughtAmount;
                        // The amount of protocol fee paid.
                        uint256 protocolFeePaid;
                    }
                    /// @dev The Exchange ERC20Proxy ID.
                    bytes4 private constant ERC20_ASSET_PROXY_ID = 0xf47261b0;
                    /// @dev Maximum uint256 value.
                    uint256 private constant MAX_UINT256 = uint256(-1);
                    /// @dev The Exchange contract.
                    IExchange public immutable exchange;
                    /// @dev The ERC20Proxy address.
                    address public immutable erc20Proxy;
                    /// @dev Create this contract.
                    /// @param exchange_ The Exchange V3 instance.
                    constructor(IExchange exchange_)
                        public
                        Transformer()
                    {
                        exchange = exchange_;
                        erc20Proxy = exchange_.getAssetProxy(ERC20_ASSET_PROXY_ID);
                    }
                    /// @dev Sell this contract's entire balance of of `sellToken` in exchange
                    ///      for `buyToken` by filling `orders`. Protocol fees should be attached
                    ///      to this call. `buyToken` and excess ETH will be transferred back to the caller.
                    /// @param data_ ABI-encoded `TransformData`.
                    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
                    function transform(
                        bytes32, // callDataHash,
                        address payable, // taker,
                        bytes calldata data_
                    )
                        external
                        override
                        returns (bytes4 success)
                    {
                        TransformData memory data = abi.decode(data_, (TransformData));
                        // Validate data fields.
                        if (data.sellToken.isTokenETH() || data.buyToken.isTokenETH()) {
                            LibTransformERC20RichErrors.InvalidTransformDataError(
                                LibTransformERC20RichErrors.InvalidTransformDataErrorCode.INVALID_TOKENS,
                                data_
                            ).rrevert();
                        }
                        if (data.orders.length != data.signatures.length) {
                            LibTransformERC20RichErrors.InvalidTransformDataError(
                                LibTransformERC20RichErrors.InvalidTransformDataErrorCode.INVALID_ARRAY_LENGTH,
                                data_
                            ).rrevert();
                        }
                        if (data.side == Side.Sell && data.fillAmount == MAX_UINT256) {
                            // If `sellAmount == -1 then we are selling
                            // the entire balance of `sellToken`. This is useful in cases where
                            // the exact sell amount is not exactly known in advance, like when
                            // unwrapping Chai/cUSDC/cDAI.
                            data.fillAmount = data.sellToken.getTokenBalanceOf(address(this));
                        }
                        // Approve the ERC20 proxy to spend `sellToken`.
                        data.sellToken.approveIfBelow(erc20Proxy, data.fillAmount);
                        // Fill the orders.
                        uint256 singleProtocolFee = exchange.protocolFeeMultiplier().safeMul(tx.gasprice);
                        uint256 ethRemaining = address(this).balance;
                        uint256 boughtAmount = 0;
                        uint256 soldAmount = 0;
                        for (uint256 i = 0; i < data.orders.length; ++i) {
                            // Check if we've hit our targets.
                            if (data.side == Side.Sell) {
                                // Market sell check.
                                if (soldAmount >= data.fillAmount) {
                                    break;
                                }
                            } else {
                                // Market buy check.
                                if (boughtAmount >= data.fillAmount) {
                                    break;
                                }
                            }
                            // Ensure we have enough ETH to cover the protocol fee.
                            if (ethRemaining < singleProtocolFee) {
                                LibTransformERC20RichErrors
                                    .InsufficientProtocolFeeError(ethRemaining, singleProtocolFee)
                                    .rrevert();
                            }
                            // Fill the order.
                            FillOrderResults memory results;
                            if (data.side == Side.Sell) {
                                // Market sell.
                                results = _sellToOrder(
                                    data.buyToken,
                                    data.sellToken,
                                    data.orders[i],
                                    data.signatures[i],
                                    data.fillAmount.safeSub(soldAmount).min256(
                                        data.maxOrderFillAmounts.length > i
                                        ? data.maxOrderFillAmounts[i]
                                        : MAX_UINT256
                                    ),
                                    singleProtocolFee
                                );
                            } else {
                                // Market buy.
                                results = _buyFromOrder(
                                    data.buyToken,
                                    data.sellToken,
                                    data.orders[i],
                                    data.signatures[i],
                                    data.fillAmount.safeSub(boughtAmount).min256(
                                        data.maxOrderFillAmounts.length > i
                                        ? data.maxOrderFillAmounts[i]
                                        : MAX_UINT256
                                    ),
                                    singleProtocolFee
                                );
                            }
                            // Accumulate totals.
                            soldAmount = soldAmount.safeAdd(results.takerTokenSoldAmount);
                            boughtAmount = boughtAmount.safeAdd(results.makerTokenBoughtAmount);
                            ethRemaining = ethRemaining.safeSub(results.protocolFeePaid);
                        }
                        // Ensure we hit our targets.
                        if (data.side == Side.Sell) {
                            // Market sell check.
                            if (soldAmount < data.fillAmount) {
                                LibTransformERC20RichErrors
                                    .IncompleteFillSellQuoteError(
                                        address(data.sellToken),
                                        soldAmount,
                                        data.fillAmount
                                    ).rrevert();
                            }
                        } else {
                            // Market buy check.
                            if (boughtAmount < data.fillAmount) {
                                LibTransformERC20RichErrors
                                    .IncompleteFillBuyQuoteError(
                                        address(data.buyToken),
                                        boughtAmount,
                                        data.fillAmount
                                    ).rrevert();
                            }
                        }
                        return LibERC20Transformer.TRANSFORMER_SUCCESS;
                    }
                    /// @dev Try to sell up to `sellAmount` from an order.
                    /// @param makerToken The maker/buy token.
                    /// @param takerToken The taker/sell token.
                    /// @param order The order to fill.
                    /// @param signature The signature for `order`.
                    /// @param sellAmount Amount of taker token to sell.
                    /// @param protocolFee The protocol fee needed to fill `order`.
                    function _sellToOrder(
                        IERC20TokenV06 makerToken,
                        IERC20TokenV06 takerToken,
                        IExchange.Order memory order,
                        bytes memory signature,
                        uint256 sellAmount,
                        uint256 protocolFee
                    )
                        private
                        returns (FillOrderResults memory results)
                    {
                        IERC20TokenV06 takerFeeToken =
                            _getTokenFromERC20AssetData(order.takerFeeAssetData);
                        uint256 takerTokenFillAmount = sellAmount;
                        if (order.takerFee != 0) {
                            if (takerFeeToken == makerToken) {
                                // Taker fee is payable in the maker token, so we need to
                                // approve the proxy to spend the maker token.
                                // It isn't worth computing the actual taker fee
                                // since `approveIfBelow()` will set the allowance to infinite. We
                                // just need a reasonable upper bound to avoid unnecessarily re-approving.
                                takerFeeToken.approveIfBelow(erc20Proxy, order.takerFee);
                            } else if (takerFeeToken == takerToken){
                                // Taker fee is payable in the taker token, so we need to
                                // reduce the fill amount to cover the fee.
                                // takerTokenFillAmount' =
                                //   (takerTokenFillAmount * order.takerAssetAmount) /
                                //   (order.takerAssetAmount + order.takerFee)
                                takerTokenFillAmount = LibMathV06.getPartialAmountCeil(
                                    order.takerAssetAmount,
                                    order.takerAssetAmount.safeAdd(order.takerFee),
                                    sellAmount
                                );
                            } else {
                                //  Only support taker or maker asset denominated taker fees.
                                LibTransformERC20RichErrors.InvalidTakerFeeTokenError(
                                    address(takerFeeToken)
                                ).rrevert();
                            }
                        }
                        // Clamp fill amount to order size.
                        takerTokenFillAmount = LibSafeMathV06.min256(
                            takerTokenFillAmount,
                            order.takerAssetAmount
                        );
                        // Perform the fill.
                        return _fillOrder(
                            order,
                            signature,
                            takerTokenFillAmount,
                            protocolFee,
                            makerToken,
                            takerFeeToken == takerToken
                        );
                    }
                    /// @dev Try to buy up to `buyAmount` from an order.
                    /// @param makerToken The maker/buy token.
                    /// @param takerToken The taker/sell token.
                    /// @param order The order to fill.
                    /// @param signature The signature for `order`.
                    /// @param buyAmount Amount of maker token to buy.
                    /// @param protocolFee The protocol fee needed to fill `order`.
                    function _buyFromOrder(
                        IERC20TokenV06 makerToken,
                        IERC20TokenV06 takerToken,
                        IExchange.Order memory order,
                        bytes memory signature,
                        uint256 buyAmount,
                        uint256 protocolFee
                    )
                        private
                        returns (FillOrderResults memory results)
                    {
                        IERC20TokenV06 takerFeeToken =
                            _getTokenFromERC20AssetData(order.takerFeeAssetData);
                        // Compute the default taker token fill amount.
                        uint256 takerTokenFillAmount = LibMathV06.getPartialAmountCeil(
                            buyAmount,
                            order.makerAssetAmount,
                            order.takerAssetAmount
                        );
                        if (order.takerFee != 0) {
                            if (takerFeeToken == makerToken) {
                                // Taker fee is payable in the maker token.
                                // Adjust the taker token fill amount to account for maker
                                // tokens being lost to the taker fee.
                                // takerTokenFillAmount' =
                                //  (order.takerAssetAmount * buyAmount) /
                                //  (order.makerAssetAmount - order.takerFee)
                                takerTokenFillAmount = LibMathV06.getPartialAmountCeil(
                                    buyAmount,
                                    order.makerAssetAmount.safeSub(order.takerFee),
                                    order.takerAssetAmount
                                );
                                // Approve the proxy to spend the maker token.
                                // It isn't worth computing the actual taker fee
                                // since `approveIfBelow()` will set the allowance to infinite. We
                                // just need a reasonable upper bound to avoid unnecessarily re-approving.
                                takerFeeToken.approveIfBelow(erc20Proxy, order.takerFee);
                            } else if (takerFeeToken != takerToken) {
                                //  Only support taker or maker asset denominated taker fees.
                                LibTransformERC20RichErrors.InvalidTakerFeeTokenError(
                                    address(takerFeeToken)
                                ).rrevert();
                            }
                        }
                        // Clamp to order size.
                        takerTokenFillAmount = LibSafeMathV06.min256(
                            order.takerAssetAmount,
                            takerTokenFillAmount
                        );
                        // Perform the fill.
                        return _fillOrder(
                            order,
                            signature,
                            takerTokenFillAmount,
                            protocolFee,
                            makerToken,
                            takerFeeToken == takerToken
                        );
                    }
                    /// @dev Attempt to fill an order. If the fill reverts, the revert will be
                    ///      swallowed and `results` will be zeroed out.
                    /// @param order The order to fill.
                    /// @param signature The order signature.
                    /// @param takerAssetFillAmount How much taker asset to fill.
                    /// @param protocolFee The protocol fee needed to fill this order.
                    /// @param makerToken The maker token.
                    /// @param isTakerFeeInTakerToken Whether the taker fee token is the same as the
                    ///        taker token.
                    function _fillOrder(
                        IExchange.Order memory order,
                        bytes memory signature,
                        uint256 takerAssetFillAmount,
                        uint256 protocolFee,
                        IERC20TokenV06 makerToken,
                        bool isTakerFeeInTakerToken
                    )
                        private
                        returns (FillOrderResults memory results)
                    {
                        // Track changes in the maker token balance.
                        uint256 initialMakerTokenBalance = makerToken.balanceOf(address(this));
                        try
                            exchange.fillOrder
                                {value: protocolFee}
                                (order, takerAssetFillAmount, signature)
                            returns (IExchange.FillResults memory fillResults)
                        {
                            // Update maker quantity based on changes in token balances.
                            results.makerTokenBoughtAmount = makerToken.balanceOf(address(this))
                                .safeSub(initialMakerTokenBalance);
                            // We can trust the other fill result quantities.
                            results.protocolFeePaid = fillResults.protocolFeePaid;
                            results.takerTokenSoldAmount = fillResults.takerAssetFilledAmount;
                            // If the taker fee is payable in the taker asset, include the
                            // taker fee in the total amount sold.
                            if (isTakerFeeInTakerToken) {
                                results.takerTokenSoldAmount =
                                    results.takerTokenSoldAmount.safeAdd(fillResults.takerFeePaid);
                            }
                        } catch (bytes memory) {
                            // Swallow failures, leaving all results as zero.
                        }
                    }
                    /// @dev Extract the token from plain ERC20 asset data.
                    ///      If the asset-data is empty, a zero token address will be returned.
                    /// @param assetData The order asset data.
                    function _getTokenFromERC20AssetData(bytes memory assetData)
                        private
                        pure
                        returns (IERC20TokenV06 token)
                    {
                        if (assetData.length == 0) {
                            return IERC20TokenV06(address(0));
                        }
                        if (assetData.length != 36 ||
                            LibBytesV06.readBytes4(assetData, 0) != ERC20_ASSET_PROXY_ID)
                        {
                            LibTransformERC20RichErrors
                                .InvalidERC20AssetDataError(assetData)
                                .rrevert();
                        }
                        return IERC20TokenV06(LibBytesV06.readAddress(assetData, 16));
                    }
                }
                /*
                  Copyright 2019 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "./LibSafeMathV06.sol";
                import "./errors/LibRichErrorsV06.sol";
                import "./errors/LibMathRichErrorsV06.sol";
                library LibMathV06 {
                    using LibSafeMathV06 for uint256;
                    /// @dev Calculates partial value given a numerator and denominator rounded down.
                    ///      Reverts if rounding error is >= 0.1%
                    /// @param numerator Numerator.
                    /// @param denominator Denominator.
                    /// @param target Value to calculate partial of.
                    /// @return partialAmount Partial value of target rounded down.
                    function safeGetPartialAmountFloor(
                        uint256 numerator,
                        uint256 denominator,
                        uint256 target
                    )
                        internal
                        pure
                        returns (uint256 partialAmount)
                    {
                        if (isRoundingErrorFloor(
                                numerator,
                                denominator,
                                target
                        )) {
                            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.RoundingError(
                                numerator,
                                denominator,
                                target
                            ));
                        }
                        partialAmount = numerator.safeMul(target).safeDiv(denominator);
                        return partialAmount;
                    }
                    /// @dev Calculates partial value given a numerator and denominator rounded down.
                    ///      Reverts if rounding error is >= 0.1%
                    /// @param numerator Numerator.
                    /// @param denominator Denominator.
                    /// @param target Value to calculate partial of.
                    /// @return partialAmount Partial value of target rounded up.
                    function safeGetPartialAmountCeil(
                        uint256 numerator,
                        uint256 denominator,
                        uint256 target
                    )
                        internal
                        pure
                        returns (uint256 partialAmount)
                    {
                        if (isRoundingErrorCeil(
                                numerator,
                                denominator,
                                target
                        )) {
                            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.RoundingError(
                                numerator,
                                denominator,
                                target
                            ));
                        }
                        // safeDiv computes `floor(a / b)`. We use the identity (a, b integer):
                        //       ceil(a / b) = floor((a + b - 1) / b)
                        // To implement `ceil(a / b)` using safeDiv.
                        partialAmount = numerator.safeMul(target)
                            .safeAdd(denominator.safeSub(1))
                            .safeDiv(denominator);
                        return partialAmount;
                    }
                    /// @dev Calculates partial value given a numerator and denominator rounded down.
                    /// @param numerator Numerator.
                    /// @param denominator Denominator.
                    /// @param target Value to calculate partial of.
                    /// @return partialAmount Partial value of target rounded down.
                    function getPartialAmountFloor(
                        uint256 numerator,
                        uint256 denominator,
                        uint256 target
                    )
                        internal
                        pure
                        returns (uint256 partialAmount)
                    {
                        partialAmount = numerator.safeMul(target).safeDiv(denominator);
                        return partialAmount;
                    }
                    /// @dev Calculates partial value given a numerator and denominator rounded down.
                    /// @param numerator Numerator.
                    /// @param denominator Denominator.
                    /// @param target Value to calculate partial of.
                    /// @return partialAmount Partial value of target rounded up.
                    function getPartialAmountCeil(
                        uint256 numerator,
                        uint256 denominator,
                        uint256 target
                    )
                        internal
                        pure
                        returns (uint256 partialAmount)
                    {
                        // safeDiv computes `floor(a / b)`. We use the identity (a, b integer):
                        //       ceil(a / b) = floor((a + b - 1) / b)
                        // To implement `ceil(a / b)` using safeDiv.
                        partialAmount = numerator.safeMul(target)
                            .safeAdd(denominator.safeSub(1))
                            .safeDiv(denominator);
                        return partialAmount;
                    }
                    /// @dev Checks if rounding error >= 0.1% when rounding down.
                    /// @param numerator Numerator.
                    /// @param denominator Denominator.
                    /// @param target Value to multiply with numerator/denominator.
                    /// @return isError Rounding error is present.
                    function isRoundingErrorFloor(
                        uint256 numerator,
                        uint256 denominator,
                        uint256 target
                    )
                        internal
                        pure
                        returns (bool isError)
                    {
                        if (denominator == 0) {
                            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.DivisionByZeroError());
                        }
                        // The absolute rounding error is the difference between the rounded
                        // value and the ideal value. The relative rounding error is the
                        // absolute rounding error divided by the absolute value of the
                        // ideal value. This is undefined when the ideal value is zero.
                        //
                        // The ideal value is `numerator * target / denominator`.
                        // Let's call `numerator * target % denominator` the remainder.
                        // The absolute error is `remainder / denominator`.
                        //
                        // When the ideal value is zero, we require the absolute error to
                        // be zero. Fortunately, this is always the case. The ideal value is
                        // zero iff `numerator == 0` and/or `target == 0`. In this case the
                        // remainder and absolute error are also zero.
                        if (target == 0 || numerator == 0) {
                            return false;
                        }
                        // Otherwise, we want the relative rounding error to be strictly
                        // less than 0.1%.
                        // The relative error is `remainder / (numerator * target)`.
                        // We want the relative error less than 1 / 1000:
                        //        remainder / (numerator * denominator)  <  1 / 1000
                        // or equivalently:
                        //        1000 * remainder  <  numerator * target
                        // so we have a rounding error iff:
                        //        1000 * remainder  >=  numerator * target
                        uint256 remainder = mulmod(
                            target,
                            numerator,
                            denominator
                        );
                        isError = remainder.safeMul(1000) >= numerator.safeMul(target);
                        return isError;
                    }
                    /// @dev Checks if rounding error >= 0.1% when rounding up.
                    /// @param numerator Numerator.
                    /// @param denominator Denominator.
                    /// @param target Value to multiply with numerator/denominator.
                    /// @return isError Rounding error is present.
                    function isRoundingErrorCeil(
                        uint256 numerator,
                        uint256 denominator,
                        uint256 target
                    )
                        internal
                        pure
                        returns (bool isError)
                    {
                        if (denominator == 0) {
                            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.DivisionByZeroError());
                        }
                        // See the comments in `isRoundingError`.
                        if (target == 0 || numerator == 0) {
                            // When either is zero, the ideal value and rounded value are zero
                            // and there is no rounding error. (Although the relative error
                            // is undefined.)
                            return false;
                        }
                        // Compute remainder as before
                        uint256 remainder = mulmod(
                            target,
                            numerator,
                            denominator
                        );
                        remainder = denominator.safeSub(remainder) % denominator;
                        isError = remainder.safeMul(1000) >= numerator.safeMul(target);
                        return isError;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibMathRichErrorsV06 {
                    // bytes4(keccak256("DivisionByZeroError()"))
                    bytes internal constant DIVISION_BY_ZERO_ERROR =
                        hex"a791837c";
                    // bytes4(keccak256("RoundingError(uint256,uint256,uint256)"))
                    bytes4 internal constant ROUNDING_ERROR_SELECTOR =
                        0x339f3de2;
                    // solhint-disable func-name-mixedcase
                    function DivisionByZeroError()
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return DIVISION_BY_ZERO_ERROR;
                    }
                    function RoundingError(
                        uint256 numerator,
                        uint256 denominator,
                        uint256 target
                    )
                        internal
                        pure
                        returns (bytes memory)
                    {
                        return abi.encodeWithSelector(
                            ROUNDING_ERROR_SELECTOR,
                            numerator,
                            denominator,
                            target
                        );
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                /// @dev Interface to the V3 Exchange.
                interface IExchange {
                    /// @dev V3 Order structure.
                    struct Order {
                        // Address that created the order.
                        address makerAddress;
                        // Address that is allowed to fill the order.
                        // If set to 0, any address is allowed to fill the order.
                        address takerAddress;
                        // Address that will recieve fees when order is filled.
                        address feeRecipientAddress;
                        // Address that is allowed to call Exchange contract methods that affect this order.
                        // If set to 0, any address is allowed to call these methods.
                        address senderAddress;
                        // Amount of makerAsset being offered by maker. Must be greater than 0.
                        uint256 makerAssetAmount;
                        // Amount of takerAsset being bid on by maker. Must be greater than 0.
                        uint256 takerAssetAmount;
                        // Fee paid to feeRecipient by maker when order is filled.
                        uint256 makerFee;
                        // Fee paid to feeRecipient by taker when order is filled.
                        uint256 takerFee;
                        // Timestamp in seconds at which order expires.
                        uint256 expirationTimeSeconds;
                        // Arbitrary number to facilitate uniqueness of the order's hash.
                        uint256 salt;
                        // Encoded data that can be decoded by a specified proxy contract when transferring makerAsset.
                        // The leading bytes4 references the id of the asset proxy.
                        bytes makerAssetData;
                        // Encoded data that can be decoded by a specified proxy contract when transferring takerAsset.
                        // The leading bytes4 references the id of the asset proxy.
                        bytes takerAssetData;
                        // Encoded data that can be decoded by a specified proxy contract when transferring makerFeeAsset.
                        // The leading bytes4 references the id of the asset proxy.
                        bytes makerFeeAssetData;
                        // Encoded data that can be decoded by a specified proxy contract when transferring takerFeeAsset.
                        // The leading bytes4 references the id of the asset proxy.
                        bytes takerFeeAssetData;
                    }
                    /// @dev V3 `fillOrder()` results.`
                    struct FillResults {
                        // Total amount of makerAsset(s) filled.
                        uint256 makerAssetFilledAmount;
                        // Total amount of takerAsset(s) filled.
                        uint256 takerAssetFilledAmount;
                        // Total amount of fees paid by maker(s) to feeRecipient(s).
                        uint256 makerFeePaid;
                        // Total amount of fees paid by taker to feeRecipients(s).
                        uint256 takerFeePaid;
                        // Total amount of fees paid by taker to the staking contract.
                        uint256 protocolFeePaid;
                    }
                    /// @dev Fills the input order.
                    /// @param order Order struct containing order specifications.
                    /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
                    /// @param signature Proof that order has been created by maker.
                    /// @return fillResults Amounts filled and fees paid by maker and taker.
                    function fillOrder(
                        Order calldata order,
                        uint256 takerAssetFillAmount,
                        bytes calldata signature
                    )
                        external
                        payable
                        returns (FillResults memory fillResults);
                    /// @dev Returns the protocolFeeMultiplier
                    /// @return multiplier The multiplier for protocol fees.
                    function protocolFeeMultiplier()
                        external
                        view
                        returns (uint256 multiplier);
                    /// @dev Gets an asset proxy.
                    /// @param assetProxyId Id of the asset proxy.
                    /// @return proxyAddress The asset proxy registered to assetProxyId.
                    ///         Returns 0x0 if no proxy is registered.
                    function getAssetProxy(bytes4 assetProxyId)
                        external
                        view
                        returns (address proxyAddress);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
                import "../errors/LibTransformERC20RichErrors.sol";
                import "./Transformer.sol";
                import "./LibERC20Transformer.sol";
                /// @dev A transformer that transfers tokens to the taker.
                contract PayTakerTransformer is
                    Transformer
                {
                    // solhint-disable no-empty-blocks
                    using LibRichErrorsV06 for bytes;
                    using LibSafeMathV06 for uint256;
                    using LibERC20Transformer for IERC20TokenV06;
                    /// @dev Transform data to ABI-encode and pass into `transform()`.
                    struct TransformData {
                        // The tokens to transfer to the taker.
                        IERC20TokenV06[] tokens;
                        // Amount of each token in `tokens` to transfer to the taker.
                        // `uint(-1)` will transfer the entire balance.
                        uint256[] amounts;
                    }
                    /// @dev Maximum uint256 value.
                    uint256 private constant MAX_UINT256 = uint256(-1);
                    /// @dev Create this contract.
                    constructor()
                        public
                        Transformer()
                    {}
                    /// @dev Forwards tokens to the taker.
                    /// @param taker The taker address (caller of `TransformERC20.transformERC20()`).
                    /// @param data_ ABI-encoded `TransformData`, indicating which tokens to transfer.
                    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
                    function transform(
                        bytes32, // callDataHash,
                        address payable taker,
                        bytes calldata data_
                    )
                        external
                        override
                        returns (bytes4 success)
                    {
                        TransformData memory data = abi.decode(data_, (TransformData));
                        // Transfer tokens directly to the taker.
                        for (uint256 i = 0; i < data.tokens.length; ++i) {
                            // The `amounts` array can be shorter than the `tokens` array.
                            // Missing elements are treated as `uint256(-1)`.
                            uint256 amount = data.amounts.length > i ? data.amounts[i] : uint256(-1);
                            if (amount == MAX_UINT256) {
                                amount = data.tokens[i].getTokenBalanceOf(address(this));
                            }
                            if (amount != 0) {
                                data.tokens[i].transformerTransfer(taker, amount);
                            }
                        }
                        return LibERC20Transformer.TRANSFORMER_SUCCESS;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
                import "../errors/LibTransformERC20RichErrors.sol";
                import "./Transformer.sol";
                import "./LibERC20Transformer.sol";
                /// @dev A transformer that wraps or unwraps WETH.
                contract WethTransformer is
                    Transformer
                {
                    using LibRichErrorsV06 for bytes;
                    using LibSafeMathV06 for uint256;
                    using LibERC20Transformer for IERC20TokenV06;
                    /// @dev Transform data to ABI-encode and pass into `transform()`.
                    struct TransformData {
                        // The token to wrap/unwrap. Must be either ETH or WETH.
                        IERC20TokenV06 token;
                        // Amount of `token` to wrap or unwrap.
                        // `uint(-1)` will unwrap the entire balance.
                        uint256 amount;
                    }
                    /// @dev The WETH contract address.
                    IEtherTokenV06 public immutable weth;
                    /// @dev Maximum uint256 value.
                    uint256 private constant MAX_UINT256 = uint256(-1);
                    /// @dev Construct the transformer and store the WETH address in an immutable.
                    /// @param weth_ The weth token.
                    constructor(IEtherTokenV06 weth_)
                        public
                        Transformer()
                    {
                        weth = weth_;
                    }
                    /// @dev Wraps and unwraps WETH.
                    /// @param data_ ABI-encoded `TransformData`, indicating which token to wrap/umwrap.
                    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
                    function transform(
                        bytes32, // callDataHash,
                        address payable, // taker,
                        bytes calldata data_
                    )
                        external
                        override
                        returns (bytes4 success)
                    {
                        TransformData memory data = abi.decode(data_, (TransformData));
                        if (!data.token.isTokenETH() && data.token != weth) {
                            LibTransformERC20RichErrors.InvalidTransformDataError(
                                LibTransformERC20RichErrors.InvalidTransformDataErrorCode.INVALID_TOKENS,
                                data_
                            ).rrevert();
                        }
                        uint256 amount = data.amount;
                        if (amount == MAX_UINT256) {
                            amount = data.token.getTokenBalanceOf(address(this));
                        }
                        if (amount != 0) {
                            if (data.token.isTokenETH()) {
                                // Wrap ETH.
                                weth.deposit{value: amount}();
                            } else {
                                // Unwrap WETH.
                                weth.withdraw(amount);
                            }
                        }
                        return LibERC20Transformer.TRANSFORMER_SUCCESS;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "./IERC20TokenV06.sol";
                interface IEtherTokenV06 is
                    IERC20TokenV06
                {
                    /// @dev Wrap ether.
                    function deposit() external payable;
                    /// @dev Unwrap ether.
                    function withdraw(uint256 amount) external;
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                interface ITestSimpleFunctionRegistryFeature {
                    function testFn() external view returns (uint256 id);
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                contract TestCallTarget {
                    event CallTargetCalled(
                        address context,
                        address sender,
                        bytes data,
                        uint256 value
                    );
                    bytes4 private constant MAGIC_BYTES = 0x12345678;
                    bytes private constant REVERTING_DATA = hex"1337";
                    fallback() external payable {
                        if (keccak256(msg.data) == keccak256(REVERTING_DATA)) {
                            revert("TestCallTarget/REVERT");
                        }
                        emit CallTargetCalled(
                            address(this),
                            msg.sender,
                            msg.data,
                            msg.value
                        );
                        bytes4 rval = MAGIC_BYTES;
                        assembly {
                            mstore(0, rval)
                            return(0, 32)
                        }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                contract TestDelegateCaller {
                    function executeDelegateCall(
                        address target,
                        bytes calldata callData
                    )
                        external
                    {
                        (bool success, bytes memory resultData) = target.delegatecall(callData);
                        if (!success) {
                            assembly { revert(add(resultData, 32), mload(resultData)) }
                        }
                        assembly { return(add(resultData, 32), mload(resultData)) }
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
                import "../src/vendor/v3/IExchange.sol";
                import "./TestMintableERC20Token.sol";
                contract TestFillQuoteTransformerExchange {
                    struct FillBehavior {
                        // How much of the order is filled, in taker asset amount.
                        uint256 filledTakerAssetAmount;
                        // Scaling for maker assets minted, in 1e18.
                        uint256 makerAssetMintRatio;
                    }
                    uint256 private constant PROTOCOL_FEE_MULTIPLIER = 1337;
                    using LibSafeMathV06 for uint256;
                    function fillOrder(
                        IExchange.Order calldata order,
                        uint256 takerAssetFillAmount,
                        bytes calldata signature
                    )
                        external
                        payable
                        returns (IExchange.FillResults memory fillResults)
                    {
                        require(
                            signature.length != 0,
                            "TestFillQuoteTransformerExchange/INVALID_SIGNATURE"
                        );
                        // The signature is the ABI-encoded FillBehavior data.
                        FillBehavior memory behavior = abi.decode(signature, (FillBehavior));
                        uint256 protocolFee = PROTOCOL_FEE_MULTIPLIER * tx.gasprice;
                        require(
                            msg.value == protocolFee,
                            "TestFillQuoteTransformerExchange/INSUFFICIENT_PROTOCOL_FEE"
                        );
                        // Return excess protocol fee.
                        msg.sender.transfer(msg.value - protocolFee);
                        // Take taker tokens.
                        TestMintableERC20Token takerToken = _getTokenFromAssetData(order.takerAssetData);
                        takerAssetFillAmount = LibSafeMathV06.min256(
                            order.takerAssetAmount.safeSub(behavior.filledTakerAssetAmount),
                            takerAssetFillAmount
                        );
                        require(
                            takerToken.getSpendableAmount(msg.sender, address(this)) >= takerAssetFillAmount,
                            "TestFillQuoteTransformerExchange/INSUFFICIENT_TAKER_FUNDS"
                        );
                        takerToken.transferFrom(msg.sender, order.makerAddress, takerAssetFillAmount);
                        // Mint maker tokens.
                        uint256 makerAssetFilledAmount = LibMathV06.getPartialAmountFloor(
                            takerAssetFillAmount,
                            order.takerAssetAmount,
                            order.makerAssetAmount
                        );
                        TestMintableERC20Token makerToken = _getTokenFromAssetData(order.makerAssetData);
                        makerToken.mint(
                            msg.sender,
                            LibMathV06.getPartialAmountFloor(
                                behavior.makerAssetMintRatio,
                                1e18,
                                makerAssetFilledAmount
                            )
                        );
                        // Take taker fee.
                        TestMintableERC20Token takerFeeToken = _getTokenFromAssetData(order.takerFeeAssetData);
                        uint256 takerFee = LibMathV06.getPartialAmountFloor(
                            takerAssetFillAmount,
                            order.takerAssetAmount,
                            order.takerFee
                        );
                        require(
                            takerFeeToken.getSpendableAmount(msg.sender, address(this)) >= takerFee,
                            "TestFillQuoteTransformerExchange/INSUFFICIENT_TAKER_FEE_FUNDS"
                        );
                        takerFeeToken.transferFrom(msg.sender, order.feeRecipientAddress, takerFee);
                        fillResults.makerAssetFilledAmount = makerAssetFilledAmount;
                        fillResults.takerAssetFilledAmount = takerAssetFillAmount;
                        fillResults.makerFeePaid = uint256(-1);
                        fillResults.takerFeePaid = takerFee;
                        fillResults.protocolFeePaid = protocolFee;
                    }
                    function encodeBehaviorData(FillBehavior calldata behavior)
                        external
                        pure
                        returns (bytes memory encoded)
                    {
                        return abi.encode(behavior);
                    }
                    function protocolFeeMultiplier()
                        external
                        pure
                        returns (uint256)
                    {
                        return PROTOCOL_FEE_MULTIPLIER;
                    }
                    function getAssetProxy(bytes4)
                        external
                        view
                        returns (address)
                    {
                        return address(this);
                    }
                    function _getTokenFromAssetData(bytes memory assetData)
                        private
                        pure
                        returns (TestMintableERC20Token token)
                    {
                        return TestMintableERC20Token(LibBytesV06.readAddress(assetData, 16));
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                contract TestMintableERC20Token {
                    mapping(address => uint256) public balanceOf;
                    mapping(address => mapping(address => uint256)) public allowance;
                    function transfer(address to, uint256 amount)
                        external
                        virtual
                        returns (bool)
                    {
                        return transferFrom(msg.sender, to, amount);
                    }
                    function approve(address spender, uint256 amount)
                        external
                        virtual
                        returns (bool)
                    {
                        allowance[msg.sender][spender] = amount;
                        return true;
                    }
                    function mint(address owner, uint256 amount)
                        external
                        virtual
                    {
                        balanceOf[owner] += amount;
                    }
                    function burn(address owner, uint256 amount)
                        external
                        virtual
                    {
                        require(balanceOf[owner] >= amount, "TestMintableERC20Token/INSUFFICIENT_FUNDS");
                        balanceOf[owner] -= amount;
                    }
                    function transferFrom(address from, address to, uint256 amount)
                        public
                        virtual
                        returns (bool)
                    {
                        if (from != msg.sender) {
                            require(
                                allowance[from][msg.sender] >= amount,
                                "TestMintableERC20Token/INSUFFICIENT_ALLOWANCE"
                            );
                            allowance[from][msg.sender] -= amount;
                        }
                        require(balanceOf[from] >= amount, "TestMintableERC20Token/INSUFFICIENT_FUNDS");
                        balanceOf[from] -= amount;
                        balanceOf[to] += amount;
                        return true;
                    }
                    function getSpendableAmount(address owner, address spender)
                        external
                        view
                        returns (uint256)
                    {
                        return balanceOf[owner] < allowance[owner][spender]
                            ? balanceOf[owner]
                            : allowance[owner][spender];
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/transformers/IERC20Transformer.sol";
                import "./TestMintableERC20Token.sol";
                import "./TestTransformerHost.sol";
                contract TestFillQuoteTransformerHost is
                    TestTransformerHost
                {
                    function executeTransform(
                        IERC20Transformer transformer,
                        TestMintableERC20Token inputToken,
                        uint256 inputTokenAmount,
                        bytes calldata data
                    )
                        external
                        payable
                    {
                        if (inputTokenAmount != 0) {
                            inputToken.mint(address(this), inputTokenAmount);
                        }
                        // Have to make this call externally because transformers aren't payable.
                        this.rawExecuteTransform(transformer, bytes32(0), msg.sender, data);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                import "../src/transformers/IERC20Transformer.sol";
                import "../src/transformers/LibERC20Transformer.sol";
                contract TestTransformerHost {
                    using LibERC20Transformer for IERC20TokenV06;
                    using LibRichErrorsV06 for bytes;
                    function rawExecuteTransform(
                        IERC20Transformer transformer,
                        bytes32 callDataHash,
                        address taker,
                        bytes calldata data
                    )
                        external
                    {
                        (bool _success, bytes memory resultData) =
                            address(transformer).delegatecall(abi.encodeWithSelector(
                                transformer.transform.selector,
                                callDataHash,
                                taker,
                                data
                            ));
                        if (!_success) {
                            resultData.rrevert();
                        }
                        require(
                            abi.decode(resultData, (bytes4)) == LibERC20Transformer.TRANSFORMER_SUCCESS,
                            "TestTransformerHost/INVALID_TRANSFORMER_RESULT"
                        );
                    }
                    // solhint-disable
                    receive() external payable {}
                    // solhint-enable
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/ZeroEx.sol";
                import "../src/features/IBootstrap.sol";
                import "../src/migrations/FullMigration.sol";
                contract TestFullMigration is
                    FullMigration
                {
                    address public dieRecipient;
                    // solhint-disable-next-line no-empty-blocks
                    constructor(address payable deployer) public FullMigration(deployer) {}
                    function die(address payable ethRecipient) external override {
                        dieRecipient = ethRecipient;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/ZeroEx.sol";
                import "../src/features/IBootstrap.sol";
                import "../src/migrations/InitialMigration.sol";
                contract TestInitialMigration is
                    InitialMigration
                {
                    address public bootstrapFeature;
                    address public dieRecipient;
                    // solhint-disable-next-line no-empty-blocks
                    constructor(address deployer) public InitialMigration(deployer) {}
                    function callBootstrap(ZeroEx zeroEx) external {
                        IBootstrap(address(zeroEx)).bootstrap(address(this), new bytes(0));
                    }
                    function bootstrap(address owner, BootstrapFeatures memory features)
                        public
                        override
                        returns (bytes4 success)
                    {
                        success = InitialMigration.bootstrap(owner, features);
                        // Snoop the bootstrap feature contract.
                        bootstrapFeature = ZeroEx(address(uint160(address(this))))
                            .getFunctionImplementation(IBootstrap.bootstrap.selector);
                    }
                    function die(address payable ethRecipient) public override {
                        dieRecipient = ethRecipient;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/migrations/LibMigrate.sol";
                import "../src/features/IOwnable.sol";
                contract TestMigrator {
                    event TestMigrateCalled(
                        bytes callData,
                        address owner
                    );
                    function succeedingMigrate() external returns (bytes4 success) {
                        emit TestMigrateCalled(
                            msg.data,
                            IOwnable(address(this)).owner()
                        );
                        return LibMigrate.MIGRATE_SUCCESS;
                    }
                    function failingMigrate() external returns (bytes4 success) {
                        emit TestMigrateCalled(
                            msg.data,
                            IOwnable(address(this)).owner()
                        );
                        return 0xdeadbeef;
                    }
                    function revertingMigrate() external pure {
                        revert("OOPSIE");
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
                import "../src/transformers/IERC20Transformer.sol";
                import "../src/transformers/LibERC20Transformer.sol";
                import "./TestMintableERC20Token.sol";
                contract TestMintTokenERC20Transformer is
                    IERC20Transformer
                {
                    struct TransformData {
                        IERC20TokenV06 inputToken;
                        TestMintableERC20Token outputToken;
                        uint256 burnAmount;
                        uint256 mintAmount;
                        uint256 feeAmount;
                    }
                    event MintTransform(
                        address context,
                        address caller,
                        bytes32 callDataHash,
                        address taker,
                        bytes data,
                        uint256 inputTokenBalance,
                        uint256 ethBalance
                    );
                    function transform(
                        bytes32 callDataHash,
                        address payable taker,
                        bytes calldata data_
                    )
                        external
                        override
                        returns (bytes4 success)
                    {
                        TransformData memory data = abi.decode(data_, (TransformData));
                        emit MintTransform(
                            address(this),
                            msg.sender,
                            callDataHash,
                            taker,
                            data_,
                            data.inputToken.balanceOf(address(this)),
                            address(this).balance
                        );
                        // "Burn" input tokens.
                        data.inputToken.transfer(address(0), data.burnAmount);
                        // Mint output tokens.
                        if (LibERC20Transformer.isTokenETH(IERC20TokenV06(address(data.outputToken)))) {
                            taker.transfer(data.mintAmount);
                        } else {
                            data.outputToken.mint(
                                taker,
                                data.mintAmount
                            );
                            // Burn fees from output.
                            data.outputToken.burn(taker, data.feeAmount);
                        }
                        return LibERC20Transformer.TRANSFORMER_SUCCESS;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/fixins/FixinCommon.sol";
                contract TestSimpleFunctionRegistryFeatureImpl1 is
                    FixinCommon
                {
                    function testFn()
                        external
                        pure
                        returns (uint256 id)
                    {
                        return 1337;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/fixins/FixinCommon.sol";
                contract TestSimpleFunctionRegistryFeatureImpl2 is
                    FixinCommon
                {
                    function testFn()
                        external
                        pure
                        returns (uint256 id)
                    {
                        return 1338;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/features/TokenSpender.sol";
                contract TestTokenSpender is
                    TokenSpender
                {
                    modifier onlySelf() override {
                        _;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "./TestMintableERC20Token.sol";
                contract TestTokenSpenderERC20Token is
                    TestMintableERC20Token
                {
                    event TransferFromCalled(
                        address sender,
                        address from,
                        address to,
                        uint256 amount
                    );
                    // `transferFrom()` behavior depends on the value of `amount`.
                    uint256 constant private EMPTY_RETURN_AMOUNT = 1337;
                    uint256 constant private FALSE_RETURN_AMOUNT = 1338;
                    uint256 constant private REVERT_RETURN_AMOUNT = 1339;
                    function transferFrom(address from, address to, uint256 amount)
                        public
                        override
                        returns (bool)
                    {
                        emit TransferFromCalled(msg.sender, from, to, amount);
                        if (amount == EMPTY_RETURN_AMOUNT) {
                            assembly { return(0, 0) }
                        }
                        if (amount == FALSE_RETURN_AMOUNT) {
                            return false;
                        }
                        if (amount == REVERT_RETURN_AMOUNT) {
                            revert("TestTokenSpenderERC20Token/Revert");
                        }
                        return true;
                    }
                    function setBalanceAndAllowanceOf(
                        address owner,
                        uint256 balance,
                        address spender,
                        uint256 allowance_
                    )
                        external
                    {
                        balanceOf[owner] = balance;
                        allowance[owner][spender] = allowance_;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/features/TransformERC20.sol";
                contract TestTransformERC20 is
                    TransformERC20
                {
                    // solhint-disable no-empty-blocks
                    constructor()
                        TransformERC20()
                        public
                    {}
                    modifier onlySelf() override {
                        _;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/transformers/Transformer.sol";
                import "../src/transformers/LibERC20Transformer.sol";
                contract TestTransformerBase is
                    Transformer
                {
                    function transform(
                        bytes32,
                        address payable,
                        bytes calldata
                    )
                        external
                        override
                        returns (bytes4 success)
                    {
                        return LibERC20Transformer.TRANSFORMER_SUCCESS;
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/transformers/LibERC20Transformer.sol";
                contract TestTransformerDeployerTransformer {
                    address payable public immutable deployer;
                    constructor() public payable {
                        deployer = msg.sender;
                    }
                    modifier onlyDeployer() {
                        require(msg.sender == deployer, "TestTransformerDeployerTransformer/ONLY_DEPLOYER");
                        _;
                    }
                    function die()
                        external
                        onlyDeployer
                    {
                        selfdestruct(deployer);
                    }
                    function isDeployedByDeployer(uint32 nonce)
                        external
                        view
                        returns (bool)
                    {
                        return LibERC20Transformer.getDeployedAddress(deployer, nonce) == address(this);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "./TestMintableERC20Token.sol";
                contract TestWeth is
                    TestMintableERC20Token
                {
                    function deposit()
                        external
                        payable
                    {
                        this.mint(msg.sender, msg.value);
                    }
                    function withdraw(uint256 amount)
                        external
                    {
                        require(balanceOf[msg.sender] >= amount, "TestWeth/INSUFFICIENT_FUNDS");
                        balanceOf[msg.sender] -= amount;
                        msg.sender.transfer(amount);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/transformers/IERC20Transformer.sol";
                import "./TestMintableERC20Token.sol";
                import "./TestTransformerHost.sol";
                import "./TestWeth.sol";
                contract TestWethTransformerHost is
                    TestTransformerHost
                {
                    // solhint-disable
                    TestWeth private immutable _weth;
                    // solhint-enable
                    constructor(TestWeth weth) public {
                        _weth = weth;
                    }
                    function executeTransform(
                        uint256 wethAmount,
                        IERC20Transformer transformer,
                        bytes calldata data
                    )
                        external
                        payable
                    {
                        if (wethAmount != 0) {
                            _weth.deposit{value: wethAmount}();
                        }
                        // Have to make this call externally because transformers aren't payable.
                        this.rawExecuteTransform(transformer, bytes32(0), msg.sender, data);
                    }
                }
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "../src/fixins/FixinCommon.sol";
                import "../src/ZeroEx.sol";
                contract TestZeroExFeature is
                    FixinCommon
                {
                    event PayableFnCalled(uint256 value);
                    event NotPayableFnCalled();
                    function payableFn()
                        external
                        payable
                    {
                        emit PayableFnCalled(msg.value);
                    }
                    function notPayableFn()
                        external
                    {
                        emit NotPayableFnCalled();
                    }
                    // solhint-disable no-empty-blocks
                    function unimplmentedFn()
                        external
                    {}
                    function internalFn()
                        external
                        onlySelf
                    {}
                }
                

                File 5 of 7: WETH9
                // Copyright (C) 2015, 2016, 2017 Dapphub
                
                // This program is free software: you can redistribute it and/or modify
                // it under the terms of the GNU General Public License as published by
                // the Free Software Foundation, either version 3 of the License, or
                // (at your option) any later version.
                
                // This program is distributed in the hope that it will be useful,
                // but WITHOUT ANY WARRANTY; without even the implied warranty of
                // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                // GNU General Public License for more details.
                
                // You should have received a copy of the GNU General Public License
                // along with this program.  If not, see <http://www.gnu.org/licenses/>.
                
                pragma solidity ^0.4.18;
                
                contract WETH9 {
                    string public name     = "Wrapped Ether";
                    string public symbol   = "WETH";
                    uint8  public decimals = 18;
                
                    event  Approval(address indexed src, address indexed guy, uint wad);
                    event  Transfer(address indexed src, address indexed dst, uint wad);
                    event  Deposit(address indexed dst, uint wad);
                    event  Withdrawal(address indexed src, uint wad);
                
                    mapping (address => uint)                       public  balanceOf;
                    mapping (address => mapping (address => uint))  public  allowance;
                
                    function() public payable {
                        deposit();
                    }
                    function deposit() public payable {
                        balanceOf[msg.sender] += msg.value;
                        Deposit(msg.sender, msg.value);
                    }
                    function withdraw(uint wad) public {
                        require(balanceOf[msg.sender] >= wad);
                        balanceOf[msg.sender] -= wad;
                        msg.sender.transfer(wad);
                        Withdrawal(msg.sender, wad);
                    }
                
                    function totalSupply() public view returns (uint) {
                        return this.balance;
                    }
                
                    function approve(address guy, uint wad) public returns (bool) {
                        allowance[msg.sender][guy] = wad;
                        Approval(msg.sender, guy, wad);
                        return true;
                    }
                
                    function transfer(address dst, uint wad) public returns (bool) {
                        return transferFrom(msg.sender, dst, wad);
                    }
                
                    function transferFrom(address src, address dst, uint wad)
                        public
                        returns (bool)
                    {
                        require(balanceOf[src] >= wad);
                
                        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
                            require(allowance[src][msg.sender] >= wad);
                            allowance[src][msg.sender] -= wad;
                        }
                
                        balanceOf[src] -= wad;
                        balanceOf[dst] += wad;
                
                        Transfer(src, dst, wad);
                
                        return true;
                    }
                }
                
                
                /*
                                    GNU GENERAL PUBLIC LICENSE
                                       Version 3, 29 June 2007
                
                 Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
                 Everyone is permitted to copy and distribute verbatim copies
                 of this license document, but changing it is not allowed.
                
                                            Preamble
                
                  The GNU General Public License is a free, copyleft license for
                software and other kinds of works.
                
                  The licenses for most software and other practical works are designed
                to take away your freedom to share and change the works.  By contrast,
                the GNU General Public License is intended to guarantee your freedom to
                share and change all versions of a program--to make sure it remains free
                software for all its users.  We, the Free Software Foundation, use the
                GNU General Public License for most of our software; it applies also to
                any other work released this way by its authors.  You can apply it to
                your programs, too.
                
                  When we speak of free software, we are referring to freedom, not
                price.  Our General Public Licenses are designed to make sure that you
                have the freedom to distribute copies of free software (and charge for
                them if you wish), that you receive source code or can get it if you
                want it, that you can change the software or use pieces of it in new
                free programs, and that you know you can do these things.
                
                  To protect your rights, we need to prevent others from denying you
                these rights or asking you to surrender the rights.  Therefore, you have
                certain responsibilities if you distribute copies of the software, or if
                you modify it: responsibilities to respect the freedom of others.
                
                  For example, if you distribute copies of such a program, whether
                gratis or for a fee, you must pass on to the recipients the same
                freedoms that you received.  You must make sure that they, too, receive
                or can get the source code.  And you must show them these terms so they
                know their rights.
                
                  Developers that use the GNU GPL protect your rights with two steps:
                (1) assert copyright on the software, and (2) offer you this License
                giving you legal permission to copy, distribute and/or modify it.
                
                  For the developers' and authors' protection, the GPL clearly explains
                that there is no warranty for this free software.  For both users' and
                authors' sake, the GPL requires that modified versions be marked as
                changed, so that their problems will not be attributed erroneously to
                authors of previous versions.
                
                  Some devices are designed to deny users access to install or run
                modified versions of the software inside them, although the manufacturer
                can do so.  This is fundamentally incompatible with the aim of
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                pattern of such abuse occurs in the area of products for individuals to
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                have designed this version of the GPL to prohibit the practice for those
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                  Finally, every program is threatened constantly by software patents.
                States should not allow patents to restrict development and use of
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                avoid the special danger that patents applied to a free program could
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                patents cannot be used to render the program non-free.
                
                  The precise terms and conditions for copying, distribution and
                modification follow.
                
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                File 6 of 7: Multicaller
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.4;
                /**
                 * @title Multicaller
                 * @author vectorized.eth
                 * @notice Contract that allows for efficient aggregation
                 *         of multiple calls in a single transaction.
                 */
                contract Multicaller {
                    // =============================================================
                    //                            ERRORS
                    // =============================================================
                    /**
                     * @dev The lengths of the input arrays are not the same.
                     */
                    error ArrayLengthsMismatch();
                    // =============================================================
                    //                    AGGREGATION OPERATIONS
                    // =============================================================
                    /**
                     * @dev Aggregates multiple calls in a single transaction.
                     * @param targets  An array of addresses to call.
                     * @param data     An array of calldata to forward to the targets.
                     * @param values   How much ETH to forward to each target.
                     * @param refundTo The address to transfer any remaining ETH in the contract after the calls.
                     *                 If `address(0)`, remaining ETH will NOT be refunded.
                     *                 If `address(1)`, remaining ETH will be refunded to `msg.sender`.
                     *                 If anything else, remaining ETH will be refunded to `refundTo`.
                     * @return An array of the returndata from each call.
                     */
                    function aggregate(
                        address[] calldata targets,
                        bytes[] calldata data,
                        uint256[] calldata values,
                        address refundTo
                    ) external payable returns (bytes[] memory) {
                        assembly {
                            if iszero(and(eq(targets.length, data.length), eq(data.length, values.length))) {
                                // Store the function selector of `ArrayLengthsMismatch()`.
                                mstore(returndatasize(), 0x3b800a46)
                                // Revert with (offset, size).
                                revert(0x1c, 0x04)
                            }
                            let resultsSize := 0x40
                            if data.length {
                                let results := 0x40
                                // Left shift by 5 is equivalent to multiplying by 0x20.
                                data.length := shl(5, data.length)
                                // Copy the offsets from calldata into memory.
                                calldatacopy(results, data.offset, data.length)
                                // Offset into `results`.
                                let resultsOffset := data.length
                                // Pointer to the end of `results`.
                                let end := add(results, data.length)
                                // For deriving the calldata offsets from the `results` pointer.
                                let valuesOffsetDiff := sub(values.offset, results)
                                let targetsOffsetDiff := sub(targets.offset, results)
                                for {} 1 {} {
                                    // The offset of the current bytes in the calldata.
                                    let o := add(data.offset, mload(results))
                                    let memPtr := add(resultsOffset, 0x40)
                                    // Copy the current bytes from calldata to the memory.
                                    calldatacopy(
                                        memPtr,
                                        add(o, 0x20), // The offset of the current bytes' bytes.
                                        calldataload(o) // The length of the current bytes.
                                    )
                                    if iszero(
                                        call(
                                            gas(), // Remaining gas.
                                            calldataload(add(targetsOffsetDiff, results)), // Address to call.
                                            calldataload(add(valuesOffsetDiff, results)), // ETH to send.
                                            memPtr, // Start of input calldata in memory.
                                            calldataload(o), // Size of input calldata.
                                            0x00, // We will use returndatacopy instead.
                                            0x00 // We will use returndatacopy instead.
                                        )
                                    ) {
                                        // Bubble up the revert if the call reverts.
                                        returndatacopy(0x00, 0x00, returndatasize())
                                        revert(0x00, returndatasize())
                                    }
                                    // Append the current `resultsOffset` into `results`.
                                    mstore(results, resultsOffset)
                                    // Append the returndatasize, and the returndata.
                                    mstore(memPtr, returndatasize())
                                    returndatacopy(add(memPtr, 0x20), 0x00, returndatasize())
                                    // Advance the `resultsOffset` by `returndatasize() + 0x20`,
                                    // rounded up to the next multiple of 0x20.
                                    resultsOffset := and(add(add(resultsOffset, returndatasize()), 0x3f), not(0x1f))
                                    // Advance the `results` pointer.
                                    results := add(results, 0x20)
                                    if eq(results, end) { break }
                                }
                                resultsSize := add(resultsOffset, 0x40)
                            }
                            if refundTo {
                                // Force transfers all the remaining ETH in the contract to `refundTo`,
                                // with a gas stipend of 100000, which should be enough for most use cases.
                                // If sending via a regular call fails, force sends the ETH by
                                // creating a temporary contract which uses `SELFDESTRUCT` to force send the ETH.
                                if selfbalance() {
                                    // If `refundTo` is `address(1)`, replace it with the `msg.sender`.
                                    refundTo := xor(refundTo, mul(eq(refundTo, 1), xor(refundTo, caller())))
                                    // Transfer the ETH and check if it succeeded or not.
                                    if iszero(
                                        call(100000, refundTo, selfbalance(), codesize(), 0x00, codesize(), 0x00)
                                    ) {
                                        mstore(0x00, refundTo) // Store the address in scratch space.
                                        mstore8(0x0b, 0x73) // Opcode `PUSH20`.
                                        mstore8(0x20, 0xff) // Opcode `SELFDESTRUCT`.
                                        // We can directly use `SELFDESTRUCT` in the contract creation.
                                        // Compatible with `SENDALL`: https://eips.ethereum.org/EIPS/eip-4758
                                        if iszero(create(selfbalance(), 0x0b, 0x16)) {
                                            // Coerce gas estimation to provide enough gas for the `create` above.
                                            revert(codesize(), codesize())
                                        }
                                    }
                                }
                            }
                            mstore(0x00, 0x20) // Store the memory offset of the `results`.
                            mstore(0x20, targets.length) // Store `targets.length` into `results`.
                            // Direct return.
                            return(0x00, resultsSize)
                        }
                    }
                    /**
                     * @dev For receiving ETH.
                     *      Does nothing and returns nothing.
                     *      Called instead of `fallback()` if the calldatasize is zero.
                     */
                    receive() external payable {}
                    /**
                     * @dev Decompresses the calldata and performs a delegatecall
                     *      with the decompressed calldata to itself.
                     *
                     *      Accompanying JavaScript library to compress the calldata:
                     *      https://github.com/vectorized/solady/blob/main/js/solady.js
                     *      (See: `LibZip.cdCompress`)
                     */
                    fallback() external payable {
                        assembly {
                            // If the calldata starts with the bitwise negation of
                            // `bytes4(keccak256("aggregate(address[],bytes[],uint256[],address)"))`.
                            let s := calldataload(returndatasize())
                            if eq(shr(224, s), 0x66e0daa0) {
                                mstore(returndatasize(), not(s))
                                let o := 4
                                for { let i := o } lt(i, calldatasize()) {} {
                                    let c := byte(returndatasize(), calldataload(i))
                                    i := add(i, 1)
                                    if iszero(c) {
                                        let d := byte(returndatasize(), calldataload(i))
                                        i := add(i, 1)
                                        // Fill with either 0xff or 0x00.
                                        mstore(o, not(returndatasize()))
                                        if iszero(gt(d, 0x7f)) { codecopy(o, codesize(), add(d, 1)) }
                                        o := add(o, add(and(d, 0x7f), 1))
                                        continue
                                    }
                                    mstore8(o, c)
                                    o := add(o, 1)
                                }
                                let success := delegatecall(gas(), address(), 0x00, o, 0x00, 0x00)
                                returndatacopy(0x00, 0x00, returndatasize())
                                if iszero(success) { revert(0x00, returndatasize()) }
                                return(0x00, returndatasize())
                            }
                            revert(returndatasize(), returndatasize())
                        }
                    }
                }
                

                File 7 of 7: UniswapV3Feature
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity >=0.6.5 <0.9;
                interface IERC20Token {
                    event Transfer(address indexed from, address indexed to, uint256 value);
                    event Approval(address indexed owner, address indexed spender, uint256 value);
                    /// @dev send `value` token to `to` from `msg.sender`
                    /// @param to The address of the recipient
                    /// @param value The amount of token to be transferred
                    /// @return True if transfer was successful
                    function transfer(address to, uint256 value) external returns (bool);
                    /// @dev send `value` token to `to` from `from` on the condition it is approved by `from`
                    /// @param from The address of the sender
                    /// @param to The address of the recipient
                    /// @param value The amount of token to be transferred
                    /// @return True if transfer was successful
                    function transferFrom(address from, address to, uint256 value) external returns (bool);
                    /// @dev `msg.sender` approves `spender` to spend `value` tokens
                    /// @param spender The address of the account able to transfer the tokens
                    /// @param value The amount of wei to be approved for transfer
                    /// @return Always true if the call has enough gas to complete execution
                    function approve(address spender, uint256 value) external returns (bool);
                    /// @dev Query total supply of token
                    /// @return Total supply of token
                    function totalSupply() external view returns (uint256);
                    /// @dev Get the balance of `owner`.
                    /// @param owner The address from which the balance will be retrieved
                    /// @return Balance of owner
                    function balanceOf(address owner) external view returns (uint256);
                    /// @dev Get the allowance for `spender` to spend from `owner`.
                    /// @param owner The address of the account owning tokens
                    /// @param spender The address of the account able to transfer the tokens
                    /// @return Amount of remaining tokens allowed to spent
                    function allowance(address owner, address spender) external view returns (uint256);
                    /// @dev Get the number of decimals this token has.
                    function decimals() external view returns (uint8);
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "./IERC20Token.sol";
                interface IEtherToken is IERC20Token {
                    /// @dev Wrap ether.
                    function deposit() external payable;
                    /// @dev Unwrap ether.
                    function withdraw(uint256 amount) external;
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                import "./errors/LibRichErrorsV06.sol";
                import "./errors/LibSafeMathRichErrorsV06.sol";
                library LibSafeMathV06 {
                    function safeMul(uint256 a, uint256 b) internal pure returns (uint256) {
                        if (a == 0) {
                            return 0;
                        }
                        uint256 c = a * b;
                        if (c / a != b) {
                            LibRichErrorsV06.rrevert(
                                LibSafeMathRichErrorsV06.Uint256BinOpError(
                                    LibSafeMathRichErrorsV06.BinOpErrorCodes.MULTIPLICATION_OVERFLOW,
                                    a,
                                    b
                                )
                            );
                        }
                        return c;
                    }
                    function safeDiv(uint256 a, uint256 b) internal pure returns (uint256) {
                        if (b == 0) {
                            LibRichErrorsV06.rrevert(
                                LibSafeMathRichErrorsV06.Uint256BinOpError(
                                    LibSafeMathRichErrorsV06.BinOpErrorCodes.DIVISION_BY_ZERO,
                                    a,
                                    b
                                )
                            );
                        }
                        uint256 c = a / b;
                        return c;
                    }
                    function safeSub(uint256 a, uint256 b) internal pure returns (uint256) {
                        if (b > a) {
                            LibRichErrorsV06.rrevert(
                                LibSafeMathRichErrorsV06.Uint256BinOpError(
                                    LibSafeMathRichErrorsV06.BinOpErrorCodes.SUBTRACTION_UNDERFLOW,
                                    a,
                                    b
                                )
                            );
                        }
                        return a - b;
                    }
                    function safeAdd(uint256 a, uint256 b) internal pure returns (uint256) {
                        uint256 c = a + b;
                        if (c < a) {
                            LibRichErrorsV06.rrevert(
                                LibSafeMathRichErrorsV06.Uint256BinOpError(
                                    LibSafeMathRichErrorsV06.BinOpErrorCodes.ADDITION_OVERFLOW,
                                    a,
                                    b
                                )
                            );
                        }
                        return c;
                    }
                    function max256(uint256 a, uint256 b) internal pure returns (uint256) {
                        return a >= b ? a : b;
                    }
                    function min256(uint256 a, uint256 b) internal pure returns (uint256) {
                        return a < b ? a : b;
                    }
                    function safeMul128(uint128 a, uint128 b) internal pure returns (uint128) {
                        if (a == 0) {
                            return 0;
                        }
                        uint128 c = a * b;
                        if (c / a != b) {
                            LibRichErrorsV06.rrevert(
                                LibSafeMathRichErrorsV06.Uint256BinOpError(
                                    LibSafeMathRichErrorsV06.BinOpErrorCodes.MULTIPLICATION_OVERFLOW,
                                    a,
                                    b
                                )
                            );
                        }
                        return c;
                    }
                    function safeDiv128(uint128 a, uint128 b) internal pure returns (uint128) {
                        if (b == 0) {
                            LibRichErrorsV06.rrevert(
                                LibSafeMathRichErrorsV06.Uint256BinOpError(
                                    LibSafeMathRichErrorsV06.BinOpErrorCodes.DIVISION_BY_ZERO,
                                    a,
                                    b
                                )
                            );
                        }
                        uint128 c = a / b;
                        return c;
                    }
                    function safeSub128(uint128 a, uint128 b) internal pure returns (uint128) {
                        if (b > a) {
                            LibRichErrorsV06.rrevert(
                                LibSafeMathRichErrorsV06.Uint256BinOpError(
                                    LibSafeMathRichErrorsV06.BinOpErrorCodes.SUBTRACTION_UNDERFLOW,
                                    a,
                                    b
                                )
                            );
                        }
                        return a - b;
                    }
                    function safeAdd128(uint128 a, uint128 b) internal pure returns (uint128) {
                        uint128 c = a + b;
                        if (c < a) {
                            LibRichErrorsV06.rrevert(
                                LibSafeMathRichErrorsV06.Uint256BinOpError(
                                    LibSafeMathRichErrorsV06.BinOpErrorCodes.ADDITION_OVERFLOW,
                                    a,
                                    b
                                )
                            );
                        }
                        return c;
                    }
                    function max128(uint128 a, uint128 b) internal pure returns (uint128) {
                        return a >= b ? a : b;
                    }
                    function min128(uint128 a, uint128 b) internal pure returns (uint128) {
                        return a < b ? a : b;
                    }
                    function safeDowncastToUint128(uint256 a) internal pure returns (uint128) {
                        if (a > type(uint128).max) {
                            LibRichErrorsV06.rrevert(
                                LibSafeMathRichErrorsV06.Uint256DowncastError(
                                    LibSafeMathRichErrorsV06.DowncastErrorCodes.VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT128,
                                    a
                                )
                            );
                        }
                        return uint128(a);
                    }
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibRichErrorsV06 {
                    // bytes4(keccak256("Error(string)"))
                    bytes4 internal constant STANDARD_ERROR_SELECTOR = 0x08c379a0;
                    /// @dev ABI encode a standard, string revert error payload.
                    ///      This is the same payload that would be included by a `revert(string)`
                    ///      solidity statement. It has the function signature `Error(string)`.
                    /// @param message The error string.
                    /// @return The ABI encoded error.
                    function StandardError(string memory message) internal pure returns (bytes memory) {
                        return abi.encodeWithSelector(STANDARD_ERROR_SELECTOR, bytes(message));
                    }
                    /// @dev Reverts an encoded rich revert reason `errorData`.
                    /// @param errorData ABI encoded error data.
                    function rrevert(bytes memory errorData) internal pure {
                        assembly {
                            revert(add(errorData, 0x20), mload(errorData))
                        }
                    }
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibSafeMathRichErrorsV06 {
                    // bytes4(keccak256("Uint256BinOpError(uint8,uint256,uint256)"))
                    bytes4 internal constant UINT256_BINOP_ERROR_SELECTOR = 0xe946c1bb;
                    // bytes4(keccak256("Uint256DowncastError(uint8,uint256)"))
                    bytes4 internal constant UINT256_DOWNCAST_ERROR_SELECTOR = 0xc996af7b;
                    enum BinOpErrorCodes {
                        ADDITION_OVERFLOW,
                        MULTIPLICATION_OVERFLOW,
                        SUBTRACTION_UNDERFLOW,
                        DIVISION_BY_ZERO
                    }
                    enum DowncastErrorCodes {
                        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT32,
                        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT64,
                        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT96,
                        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT128
                    }
                    function Uint256BinOpError(BinOpErrorCodes errorCode, uint256 a, uint256 b) internal pure returns (bytes memory) {
                        return abi.encodeWithSelector(UINT256_BINOP_ERROR_SELECTOR, errorCode, a, b);
                    }
                    function Uint256DowncastError(DowncastErrorCodes errorCode, uint256 a) internal pure returns (bytes memory) {
                        return abi.encodeWithSelector(UINT256_DOWNCAST_ERROR_SELECTOR, errorCode, a);
                    }
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2020 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                interface IOwnableV06 {
                    /// @dev Emitted by Ownable when ownership is transferred.
                    /// @param previousOwner The previous owner of the contract.
                    /// @param newOwner The new owner of the contract.
                    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                    /// @dev Transfers ownership of the contract to a new address.
                    /// @param newOwner The address that will become the owner.
                    function transferOwnership(address newOwner) external;
                    /// @dev The owner of this contract.
                    /// @return ownerAddress The owner address.
                    function owner() external view returns (address ownerAddress);
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibCommonRichErrors {
                    function OnlyCallableBySelfError(address sender) internal pure returns (bytes memory) {
                        return abi.encodeWithSelector(bytes4(keccak256("OnlyCallableBySelfError(address)")), sender);
                    }
                    function IllegalReentrancyError(bytes4 selector, uint256 reentrancyFlags) internal pure returns (bytes memory) {
                        return
                            abi.encodeWithSelector(
                                bytes4(keccak256("IllegalReentrancyError(bytes4,uint256)")),
                                selector,
                                reentrancyFlags
                            );
                    }
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                library LibOwnableRichErrors {
                    function OnlyOwnerError(address sender, address owner) internal pure returns (bytes memory) {
                        return abi.encodeWithSelector(bytes4(keccak256("OnlyOwnerError(address,address)")), sender, owner);
                    }
                    function TransferOwnerToZeroError() internal pure returns (bytes memory) {
                        return abi.encodeWithSelector(bytes4(keccak256("TransferOwnerToZeroError()")));
                    }
                    function MigrateCallFailedError(address target, bytes memory resultData) internal pure returns (bytes memory) {
                        return abi.encodeWithSelector(bytes4(keccak256("MigrateCallFailedError(address,bytes)")), target, resultData);
                    }
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-erc20/src/IERC20Token.sol";
                import "@0x/contracts-erc20/src/IEtherToken.sol";
                import "../vendor/IUniswapV3Pool.sol";
                import "../migrations/LibMigrate.sol";
                import "../fixins/FixinCommon.sol";
                import "../fixins/FixinTokenSpender.sol";
                import "./interfaces/IFeature.sol";
                import "./interfaces/IUniswapV3Feature.sol";
                /// @dev VIP uniswap fill functions.
                contract UniswapV3Feature is IFeature, IUniswapV3Feature, FixinCommon, FixinTokenSpender {
                    /// @dev Name of this feature.
                    string public constant override FEATURE_NAME = "UniswapV3Feature";
                    /// @dev Version of this feature.
                    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 1, 0);
                    /// @dev WETH contract.
                    IEtherToken private immutable WETH;
                    /// @dev UniswapV3 Factory contract address prepended with '0xff' and left-aligned.
                    bytes32 private immutable UNI_FF_FACTORY_ADDRESS;
                    /// @dev UniswapV3 pool init code hash.
                    bytes32 private immutable UNI_POOL_INIT_CODE_HASH;
                    /// @dev Minimum size of an encoded swap path:
                    ///      sizeof(address(inputToken) | uint24(fee) | address(outputToken))
                    uint256 private constant SINGLE_HOP_PATH_SIZE = 20 + 3 + 20;
                    /// @dev How many bytes to skip ahead in an encoded path to start at the next hop:
                    ///      sizeof(address(inputToken) | uint24(fee))
                    uint256 private constant PATH_SKIP_HOP_SIZE = 20 + 3;
                    /// @dev The size of the swap callback data.
                    uint256 private constant SWAP_CALLBACK_DATA_SIZE = 128;
                    /// @dev Minimum tick price sqrt ratio.
                    uint160 internal constant MIN_PRICE_SQRT_RATIO = 4295128739;
                    /// @dev Minimum tick price sqrt ratio.
                    uint160 internal constant MAX_PRICE_SQRT_RATIO = 1461446703485210103287273052203988822378723970342;
                    /// @dev Mask of lower 20 bytes.
                    uint256 private constant ADDRESS_MASK = 0x00ffffffffffffffffffffffffffffffffffffffff;
                    /// @dev Mask of lower 3 bytes.
                    uint256 private constant UINT24_MASK = 0xffffff;
                    /// @dev Construct this contract.
                    /// @param weth The WETH contract.
                    /// @param uniFactory The UniswapV3 factory contract.
                    /// @param poolInitCodeHash The UniswapV3 pool init code hash.
                    constructor(IEtherToken weth, address uniFactory, bytes32 poolInitCodeHash) public {
                        WETH = weth;
                        UNI_FF_FACTORY_ADDRESS = bytes32((uint256(0xff) << 248) | (uint256(uniFactory) << 88));
                        UNI_POOL_INIT_CODE_HASH = poolInitCodeHash;
                    }
                    /// @dev Initialize and register this feature.
                    ///      Should be delegatecalled by `Migrate.migrate()`.
                    /// @return success `LibMigrate.SUCCESS` on success.
                    function migrate() external returns (bytes4 success) {
                        _registerFeatureFunction(this.sellEthForTokenToUniswapV3.selector);
                        _registerFeatureFunction(this.sellTokenForEthToUniswapV3.selector);
                        _registerFeatureFunction(this.sellTokenForTokenToUniswapV3.selector);
                        _registerFeatureFunction(this._sellTokenForTokenToUniswapV3.selector);
                        _registerFeatureFunction(this._sellHeldTokenForTokenToUniswapV3.selector);
                        _registerFeatureFunction(this.uniswapV3SwapCallback.selector);
                        return LibMigrate.MIGRATE_SUCCESS;
                    }
                    /// @dev Sell attached ETH directly against uniswap v3.
                    /// @param encodedPath Uniswap-encoded path, where the first token is WETH.
                    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
                    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
                    /// @return buyAmount Amount of the last token in the path bought.
                    function sellEthForTokenToUniswapV3(
                        bytes memory encodedPath,
                        uint256 minBuyAmount,
                        address recipient
                    ) public payable override returns (uint256 buyAmount) {
                        // Wrap ETH.
                        WETH.deposit{value: msg.value}();
                        return
                            _swap(
                                encodedPath,
                                msg.value,
                                minBuyAmount,
                                address(this), // we are payer because we hold the WETH
                                _normalizeRecipient(recipient)
                            );
                    }
                    /// @dev Sell a token for ETH directly against uniswap v3.
                    /// @param encodedPath Uniswap-encoded path, where the last token is WETH.
                    /// @param sellAmount amount of the first token in the path to sell.
                    /// @param minBuyAmount Minimum amount of ETH to buy.
                    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
                    /// @return buyAmount Amount of ETH bought.
                    function sellTokenForEthToUniswapV3(
                        bytes memory encodedPath,
                        uint256 sellAmount,
                        uint256 minBuyAmount,
                        address payable recipient
                    ) public override returns (uint256 buyAmount) {
                        buyAmount = _swap(
                            encodedPath,
                            sellAmount,
                            minBuyAmount,
                            msg.sender,
                            address(this) // we are recipient because we need to unwrap WETH
                        );
                        WETH.withdraw(buyAmount);
                        // Transfer ETH to recipient.
                        (bool success, bytes memory revertData) = _normalizeRecipient(recipient).call{value: buyAmount}("");
                        if (!success) {
                            revertData.rrevert();
                        }
                    }
                    /// @dev Sell a token for another token directly against uniswap v3.
                    /// @param encodedPath Uniswap-encoded path.
                    /// @param sellAmount amount of the first token in the path to sell.
                    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
                    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
                    /// @return buyAmount Amount of the last token in the path bought.
                    function sellTokenForTokenToUniswapV3(
                        bytes memory encodedPath,
                        uint256 sellAmount,
                        uint256 minBuyAmount,
                        address recipient
                    ) public override returns (uint256 buyAmount) {
                        buyAmount = _swap(encodedPath, sellAmount, minBuyAmount, msg.sender, _normalizeRecipient(recipient));
                    }
                    /// @dev Sell a token for another token directly against uniswap v3. Internal variant.
                    /// @param encodedPath Uniswap-encoded path.
                    /// @param sellAmount amount of the first token in the path to sell.
                    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
                    /// @param recipient The recipient of the bought tokens. Can be zero for payer.
                    /// @param payer The address to pull the sold tokens from.
                    /// @return buyAmount Amount of the last token in the path bought.
                    function _sellTokenForTokenToUniswapV3(
                        bytes memory encodedPath,
                        uint256 sellAmount,
                        uint256 minBuyAmount,
                        address recipient,
                        address payer
                    ) public override onlySelf returns (uint256 buyAmount) {
                        buyAmount = _swap(encodedPath, sellAmount, minBuyAmount, payer, _normalizeRecipient(recipient, payer));
                    }
                    /// @dev Sell a token for another token directly against uniswap v3.
                    ///      Private variant, uses tokens held by `address(this)`.
                    /// @param encodedPath Uniswap-encoded path.
                    /// @param sellAmount amount of the first token in the path to sell.
                    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
                    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
                    /// @return buyAmount Amount of the last token in the path bought.
                    function _sellHeldTokenForTokenToUniswapV3(
                        bytes memory encodedPath,
                        uint256 sellAmount,
                        uint256 minBuyAmount,
                        address recipient
                    ) public override onlySelf returns (uint256 buyAmount) {
                        buyAmount = _swap(encodedPath, sellAmount, minBuyAmount, address(this), _normalizeRecipient(recipient));
                    }
                    /// @dev The UniswapV3 pool swap callback which pays the funds requested
                    ///      by the caller/pool to the pool. Can only be called by a valid
                    ///      UniswapV3 pool.
                    /// @param amount0Delta Token0 amount owed.
                    /// @param amount1Delta Token1 amount owed.
                    /// @param data Arbitrary data forwarded from swap() caller. An ABI-encoded
                    ///        struct of: inputToken, outputToken, fee, payer
                    function uniswapV3SwapCallback(int256 amount0Delta, int256 amount1Delta, bytes calldata data) external override {
                        IERC20Token token0;
                        IERC20Token token1;
                        address payer;
                        {
                            uint24 fee;
                            // Decode the data.
                            require(data.length == SWAP_CALLBACK_DATA_SIZE, "UniswapFeature/INVALID_SWAP_CALLBACK_DATA");
                            assembly {
                                let p := add(36, calldataload(68))
                                token0 := calldataload(p)
                                token1 := calldataload(add(p, 32))
                                fee := calldataload(add(p, 64))
                                payer := calldataload(add(p, 96))
                            }
                            (token0, token1) = token0 < token1 ? (token0, token1) : (token1, token0);
                            // Only a valid pool contract can call this function.
                            require(
                                msg.sender == address(_toPool(token0, fee, token1)),
                                "UniswapV3Feature/INVALID_SWAP_CALLBACK_CALLER"
                            );
                        }
                        // Pay the amount owed to the pool.
                        if (amount0Delta > 0) {
                            _pay(token0, payer, msg.sender, uint256(amount0Delta));
                        } else if (amount1Delta > 0) {
                            _pay(token1, payer, msg.sender, uint256(amount1Delta));
                        } else {
                            revert("UniswapV3Feature/INVALID_SWAP_AMOUNTS");
                        }
                    }
                    // Executes successive swaps along an encoded uniswap path.
                    function _swap(
                        bytes memory encodedPath,
                        uint256 sellAmount,
                        uint256 minBuyAmount,
                        address payer,
                        address recipient
                    ) private returns (uint256 buyAmount) {
                        if (sellAmount != 0) {
                            require(sellAmount <= uint256(type(int256).max), "UniswapV3Feature/SELL_AMOUNT_OVERFLOW");
                            // Perform a swap for each hop in the path.
                            bytes memory swapCallbackData = new bytes(SWAP_CALLBACK_DATA_SIZE);
                            while (true) {
                                bool isPathMultiHop = _isPathMultiHop(encodedPath);
                                bool zeroForOne;
                                IUniswapV3Pool pool;
                                {
                                    (IERC20Token inputToken, uint24 fee, IERC20Token outputToken) = _decodeFirstPoolInfoFromPath(
                                        encodedPath
                                    );
                                    pool = _toPool(inputToken, fee, outputToken);
                                    zeroForOne = inputToken < outputToken;
                                    _updateSwapCallbackData(swapCallbackData, inputToken, outputToken, fee, payer);
                                }
                                (int256 amount0, int256 amount1) = pool.swap(
                                    // Intermediate tokens go to this contract.
                                    isPathMultiHop ? address(this) : recipient,
                                    zeroForOne,
                                    int256(sellAmount),
                                    zeroForOne ? MIN_PRICE_SQRT_RATIO + 1 : MAX_PRICE_SQRT_RATIO - 1,
                                    swapCallbackData
                                );
                                {
                                    int256 _buyAmount = -(zeroForOne ? amount1 : amount0);
                                    require(_buyAmount >= 0, "UniswapV3Feature/INVALID_BUY_AMOUNT");
                                    buyAmount = uint256(_buyAmount);
                                }
                                if (!isPathMultiHop) {
                                    // Done.
                                    break;
                                }
                                // Continue with next hop.
                                payer = address(this); // Subsequent hops are paid for by us.
                                sellAmount = buyAmount;
                                // Skip to next hop along path.
                                encodedPath = _shiftHopFromPathInPlace(encodedPath);
                            }
                        }
                        require(minBuyAmount <= buyAmount, "UniswapV3Feature/UNDERBOUGHT");
                    }
                    // Pay tokens from `payer` to `to`, using `transferFrom()` if
                    // `payer` != this contract.
                    function _pay(IERC20Token token, address payer, address to, uint256 amount) private {
                        if (payer != address(this)) {
                            _transferERC20TokensFrom(token, payer, to, amount);
                        } else {
                            _transferERC20Tokens(token, to, amount);
                        }
                    }
                    // Update `swapCallbackData` in place with new values.
                    function _updateSwapCallbackData(
                        bytes memory swapCallbackData,
                        IERC20Token inputToken,
                        IERC20Token outputToken,
                        uint24 fee,
                        address payer
                    ) private pure {
                        assembly {
                            let p := add(swapCallbackData, 32)
                            mstore(p, inputToken)
                            mstore(add(p, 32), outputToken)
                            mstore(add(p, 64), and(UINT24_MASK, fee))
                            mstore(add(p, 96), and(ADDRESS_MASK, payer))
                        }
                    }
                    // Compute the pool address given two tokens and a fee.
                    function _toPool(
                        IERC20Token inputToken,
                        uint24 fee,
                        IERC20Token outputToken
                    ) private view returns (IUniswapV3Pool pool) {
                        // address(keccak256(abi.encodePacked(
                        //     hex"ff",
                        //     UNI_FACTORY_ADDRESS,
                        //     keccak256(abi.encode(inputToken, outputToken, fee)),
                        //     UNI_POOL_INIT_CODE_HASH
                        // )))
                        bytes32 ffFactoryAddress = UNI_FF_FACTORY_ADDRESS;
                        bytes32 poolInitCodeHash = UNI_POOL_INIT_CODE_HASH;
                        (IERC20Token token0, IERC20Token token1) = inputToken < outputToken
                            ? (inputToken, outputToken)
                            : (outputToken, inputToken);
                        assembly {
                            let s := mload(0x40)
                            let p := s
                            mstore(p, ffFactoryAddress)
                            p := add(p, 21)
                            // Compute the inner hash in-place
                            mstore(p, token0)
                            mstore(add(p, 32), token1)
                            mstore(add(p, 64), and(UINT24_MASK, fee))
                            mstore(p, keccak256(p, 96))
                            p := add(p, 32)
                            mstore(p, poolInitCodeHash)
                            pool := and(ADDRESS_MASK, keccak256(s, 85))
                        }
                    }
                    // Return whether or not an encoded uniswap path contains more than one hop.
                    function _isPathMultiHop(bytes memory encodedPath) private pure returns (bool isMultiHop) {
                        return encodedPath.length > SINGLE_HOP_PATH_SIZE;
                    }
                    // Return the first input token, output token, and fee of an encoded uniswap path.
                    function _decodeFirstPoolInfoFromPath(
                        bytes memory encodedPath
                    ) private pure returns (IERC20Token inputToken, uint24 fee, IERC20Token outputToken) {
                        require(encodedPath.length >= SINGLE_HOP_PATH_SIZE, "UniswapV3Feature/BAD_PATH_ENCODING");
                        assembly {
                            let p := add(encodedPath, 32)
                            inputToken := shr(96, mload(p))
                            p := add(p, 20)
                            fee := shr(232, mload(p))
                            p := add(p, 3)
                            outputToken := shr(96, mload(p))
                        }
                    }
                    // Skip past the first hop of an encoded uniswap path in-place.
                    function _shiftHopFromPathInPlace(bytes memory encodedPath) private pure returns (bytes memory shiftedEncodedPath) {
                        require(encodedPath.length >= PATH_SKIP_HOP_SIZE, "UniswapV3Feature/BAD_PATH_ENCODING");
                        uint256 shiftSize = PATH_SKIP_HOP_SIZE;
                        uint256 newSize = encodedPath.length - shiftSize;
                        assembly {
                            shiftedEncodedPath := add(encodedPath, shiftSize)
                            mstore(shiftedEncodedPath, newSize)
                        }
                    }
                    // Convert null address values to alternative address.
                    function _normalizeRecipient(
                        address recipient,
                        address alternative
                    ) private pure returns (address payable normalizedRecipient) {
                        return recipient == address(0) ? payable(alternative) : payable(recipient);
                    }
                    // Convert null address values to msg.sender.
                    function _normalizeRecipient(address recipient) private view returns (address payable normalizedRecipient) {
                        return _normalizeRecipient(recipient, msg.sender);
                    }
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                /// @dev Basic interface for a feature contract.
                interface IFeature {
                    /// @dev The name of this feature set.
                    function FEATURE_NAME() external view returns (string memory name);
                    /// @dev The version of this feature set.
                    function FEATURE_VERSION() external view returns (uint256 version);
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/interfaces/IOwnableV06.sol";
                /// @dev Owner management and migration features.
                interface IOwnableFeature is IOwnableV06 {
                    /// @dev Emitted when `migrate()` is called.
                    /// @param caller The caller of `migrate()`.
                    /// @param migrator The migration contract.
                    /// @param newOwner The address of the new owner.
                    event Migrated(address caller, address migrator, address newOwner);
                    /// @dev Execute a migration function in the context of the ZeroEx contract.
                    ///      The result of the function being called should be the magic bytes
                    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
                    ///      The owner will be temporarily set to `address(this)` inside the call.
                    ///      Before returning, the owner will be set to `newOwner`.
                    /// @param target The migrator contract address.
                    /// @param newOwner The address of the new owner.
                    /// @param data The call data.
                    function migrate(address target, bytes calldata data, address newOwner) external;
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                /// @dev Basic registry management features.
                interface ISimpleFunctionRegistryFeature {
                    /// @dev A function implementation was updated via `extend()` or `rollback()`.
                    /// @param selector The function selector.
                    /// @param oldImpl The implementation contract address being replaced.
                    /// @param newImpl The replacement implementation contract address.
                    event ProxyFunctionUpdated(bytes4 indexed selector, address oldImpl, address newImpl);
                    /// @dev Roll back to a prior implementation of a function.
                    /// @param selector The function selector.
                    /// @param targetImpl The address of an older implementation of the function.
                    function rollback(bytes4 selector, address targetImpl) external;
                    /// @dev Register or replace a function.
                    /// @param selector The function selector.
                    /// @param impl The implementation contract for the function.
                    function extend(bytes4 selector, address impl) external;
                    /// @dev Retrieve the length of the rollback history for a function.
                    /// @param selector The function selector.
                    /// @return rollbackLength The number of items in the rollback history for
                    ///         the function.
                    function getRollbackLength(bytes4 selector) external view returns (uint256 rollbackLength);
                    /// @dev Retrieve an entry in the rollback history for a function.
                    /// @param selector The function selector.
                    /// @param idx The index in the rollback history.
                    /// @return impl An implementation address for the function at
                    ///         index `idx`.
                    function getRollbackEntryAtIndex(bytes4 selector, uint256 idx) external view returns (address impl);
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                /// @dev VIP uniswap v3 fill functions.
                interface IUniswapV3Feature {
                    /// @dev Sell attached ETH directly against uniswap v3.
                    /// @param encodedPath Uniswap-encoded path, where the first token is WETH.
                    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
                    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
                    /// @return buyAmount Amount of the last token in the path bought.
                    function sellEthForTokenToUniswapV3(
                        bytes memory encodedPath,
                        uint256 minBuyAmount,
                        address recipient
                    ) external payable returns (uint256 buyAmount);
                    /// @dev Sell a token for ETH directly against uniswap v3.
                    /// @param encodedPath Uniswap-encoded path, where the last token is WETH.
                    /// @param sellAmount amount of the first token in the path to sell.
                    /// @param minBuyAmount Minimum amount of ETH to buy.
                    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
                    /// @return buyAmount Amount of ETH bought.
                    function sellTokenForEthToUniswapV3(
                        bytes memory encodedPath,
                        uint256 sellAmount,
                        uint256 minBuyAmount,
                        address payable recipient
                    ) external returns (uint256 buyAmount);
                    /// @dev Sell a token for another token directly against uniswap v3.
                    /// @param encodedPath Uniswap-encoded path.
                    /// @param sellAmount amount of the first token in the path to sell.
                    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
                    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
                    /// @return buyAmount Amount of the last token in the path bought.
                    function sellTokenForTokenToUniswapV3(
                        bytes memory encodedPath,
                        uint256 sellAmount,
                        uint256 minBuyAmount,
                        address recipient
                    ) external returns (uint256 buyAmount);
                    /// @dev Sell a token for another token directly against uniswap v3. Internal variant.
                    /// @param encodedPath Uniswap-encoded path.
                    /// @param sellAmount amount of the first token in the path to sell.
                    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
                    /// @param recipient The recipient of the bought tokens. Can be zero for payer.
                    /// @param payer The address to pull the sold tokens from.
                    /// @return buyAmount Amount of the last token in the path bought.
                    function _sellTokenForTokenToUniswapV3(
                        bytes memory encodedPath,
                        uint256 sellAmount,
                        uint256 minBuyAmount,
                        address recipient,
                        address payer
                    ) external returns (uint256 buyAmount);
                    /// @dev Sell a token for another token directly against uniswap v3.
                    ///      Private variant, uses tokens held by `address(this)`.
                    /// @param encodedPath Uniswap-encoded path.
                    /// @param sellAmount amount of the first token in the path to sell.
                    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
                    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
                    /// @return buyAmount Amount of the last token in the path bought.
                    function _sellHeldTokenForTokenToUniswapV3(
                        bytes memory encodedPath,
                        uint256 sellAmount,
                        uint256 minBuyAmount,
                        address recipient
                    ) external returns (uint256 buyAmount);
                    /// @dev The UniswapV3 pool swap callback which pays the funds requested
                    ///      by the caller/pool to the pool. Can only be called by a valid
                    ///      UniswapV3 pool.
                    /// @param amount0Delta Token0 amount owed.
                    /// @param amount1Delta Token1 amount owed.
                    /// @param data Arbitrary data forwarded from swap() caller. An ABI-encoded
                    ///        struct of: inputToken, outputToken, fee, payer
                    function uniswapV3SwapCallback(int256 amount0Delta, int256 amount1Delta, bytes calldata data) external;
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "../errors/LibCommonRichErrors.sol";
                import "../errors/LibOwnableRichErrors.sol";
                import "../features/interfaces/IOwnableFeature.sol";
                import "../features/interfaces/ISimpleFunctionRegistryFeature.sol";
                /// @dev Common feature utilities.
                abstract contract FixinCommon {
                    using LibRichErrorsV06 for bytes;
                    /// @dev The implementation address of this feature.
                    address internal immutable _implementation;
                    /// @dev The caller must be this contract.
                    modifier onlySelf() virtual {
                        if (msg.sender != address(this)) {
                            LibCommonRichErrors.OnlyCallableBySelfError(msg.sender).rrevert();
                        }
                        _;
                    }
                    /// @dev The caller of this function must be the owner.
                    modifier onlyOwner() virtual {
                        {
                            address owner = IOwnableFeature(address(this)).owner();
                            if (msg.sender != owner) {
                                LibOwnableRichErrors.OnlyOwnerError(msg.sender, owner).rrevert();
                            }
                        }
                        _;
                    }
                    constructor() internal {
                        // Remember this feature's original address.
                        _implementation = address(this);
                    }
                    /// @dev Registers a function implemented by this feature at `_implementation`.
                    ///      Can and should only be called within a `migrate()`.
                    /// @param selector The selector of the function whose implementation
                    ///        is at `_implementation`.
                    function _registerFeatureFunction(bytes4 selector) internal {
                        ISimpleFunctionRegistryFeature(address(this)).extend(selector, _implementation);
                    }
                    /// @dev Encode a feature version as a `uint256`.
                    /// @param major The major version number of the feature.
                    /// @param minor The minor version number of the feature.
                    /// @param revision The revision number of the feature.
                    /// @return encodedVersion The encoded version number.
                    function _encodeVersion(
                        uint32 major,
                        uint32 minor,
                        uint32 revision
                    ) internal pure returns (uint256 encodedVersion) {
                        return (uint256(major) << 64) | (uint256(minor) << 32) | uint256(revision);
                    }
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-erc20/src/IERC20Token.sol";
                import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
                /// @dev Helpers for moving tokens around.
                abstract contract FixinTokenSpender {
                    // Mask of the lower 20 bytes of a bytes32.
                    uint256 private constant ADDRESS_MASK = 0x000000000000000000000000ffffffffffffffffffffffffffffffffffffffff;
                    /// @dev Transfers ERC20 tokens from `owner` to `to`.
                    /// @param token The token to spend.
                    /// @param owner The owner of the tokens.
                    /// @param to The recipient of the tokens.
                    /// @param amount The amount of `token` to transfer.
                    function _transferERC20TokensFrom(IERC20Token token, address owner, address to, uint256 amount) internal {
                        require(address(token) != address(this), "FixinTokenSpender/CANNOT_INVOKE_SELF");
                        assembly {
                            let ptr := mload(0x40) // free memory pointer
                            // selector for transferFrom(address,address,uint256)
                            mstore(ptr, 0x23b872dd00000000000000000000000000000000000000000000000000000000)
                            mstore(add(ptr, 0x04), and(owner, ADDRESS_MASK))
                            mstore(add(ptr, 0x24), and(to, ADDRESS_MASK))
                            mstore(add(ptr, 0x44), amount)
                            let success := call(gas(), and(token, ADDRESS_MASK), 0, ptr, 0x64, ptr, 32)
                            let rdsize := returndatasize()
                            // Check for ERC20 success. ERC20 tokens should return a boolean,
                            // but some don't. We accept 0-length return data as success, or at
                            // least 32 bytes that starts with a 32-byte boolean true.
                            success := and(
                                success, // call itself succeeded
                                or(
                                    iszero(rdsize), // no return data, or
                                    and(
                                        iszero(lt(rdsize, 32)), // at least 32 bytes
                                        eq(mload(ptr), 1) // starts with uint256(1)
                                    )
                                )
                            )
                            if iszero(success) {
                                returndatacopy(ptr, 0, rdsize)
                                revert(ptr, rdsize)
                            }
                        }
                    }
                    /// @dev Transfers ERC20 tokens from ourselves to `to`.
                    /// @param token The token to spend.
                    /// @param to The recipient of the tokens.
                    /// @param amount The amount of `token` to transfer.
                    function _transferERC20Tokens(IERC20Token token, address to, uint256 amount) internal {
                        require(address(token) != address(this), "FixinTokenSpender/CANNOT_INVOKE_SELF");
                        assembly {
                            let ptr := mload(0x40) // free memory pointer
                            // selector for transfer(address,uint256)
                            mstore(ptr, 0xa9059cbb00000000000000000000000000000000000000000000000000000000)
                            mstore(add(ptr, 0x04), and(to, ADDRESS_MASK))
                            mstore(add(ptr, 0x24), amount)
                            let success := call(gas(), and(token, ADDRESS_MASK), 0, ptr, 0x44, ptr, 32)
                            let rdsize := returndatasize()
                            // Check for ERC20 success. ERC20 tokens should return a boolean,
                            // but some don't. We accept 0-length return data as success, or at
                            // least 32 bytes that starts with a 32-byte boolean true.
                            success := and(
                                success, // call itself succeeded
                                or(
                                    iszero(rdsize), // no return data, or
                                    and(
                                        iszero(lt(rdsize, 32)), // at least 32 bytes
                                        eq(mload(ptr), 1) // starts with uint256(1)
                                    )
                                )
                            )
                            if iszero(success) {
                                returndatacopy(ptr, 0, rdsize)
                                revert(ptr, rdsize)
                            }
                        }
                    }
                    /// @dev Transfers some amount of ETH to the given recipient and
                    ///      reverts if the transfer fails.
                    /// @param recipient The recipient of the ETH.
                    /// @param amount The amount of ETH to transfer.
                    function _transferEth(address payable recipient, uint256 amount) internal {
                        if (amount > 0) {
                            (bool success, ) = recipient.call{value: amount}("");
                            require(success, "FixinTokenSpender::_transferEth/TRANSFER_FAILED");
                        }
                    }
                    /// @dev Gets the maximum amount of an ERC20 token `token` that can be
                    ///      pulled from `owner` by this address.
                    /// @param token The token to spend.
                    /// @param owner The owner of the tokens.
                    /// @return amount The amount of tokens that can be pulled.
                    function _getSpendableERC20BalanceOf(IERC20Token token, address owner) internal view returns (uint256) {
                        return LibSafeMathV06.min256(token.allowance(owner, address(this)), token.balanceOf(owner));
                    }
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.5;
                pragma experimental ABIEncoderV2;
                import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
                import "../errors/LibOwnableRichErrors.sol";
                library LibMigrate {
                    /// @dev Magic bytes returned by a migrator to indicate success.
                    ///      This is `keccack('MIGRATE_SUCCESS')`.
                    bytes4 internal constant MIGRATE_SUCCESS = 0x2c64c5ef;
                    using LibRichErrorsV06 for bytes;
                    /// @dev Perform a delegatecall and ensure it returns the magic bytes.
                    /// @param target The call target.
                    /// @param data The call data.
                    function delegatecallMigrateFunction(address target, bytes memory data) internal {
                        (bool success, bytes memory resultData) = target.delegatecall(data);
                        if (!success || resultData.length != 32 || abi.decode(resultData, (bytes4)) != MIGRATE_SUCCESS) {
                            LibOwnableRichErrors.MigrateCallFailedError(target, resultData).rrevert();
                        }
                    }
                }
                // SPDX-License-Identifier: Apache-2.0
                /*
                  Copyright 2023 ZeroEx Intl.
                  Licensed under the Apache License, Version 2.0 (the "License");
                  you may not use this file except in compliance with the License.
                  You may obtain a copy of the License at
                    http://www.apache.org/licenses/LICENSE-2.0
                  Unless required by applicable law or agreed to in writing, software
                  distributed under the License is distributed on an "AS IS" BASIS,
                  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                  See the License for the specific language governing permissions and
                  limitations under the License.
                */
                pragma solidity ^0.6.12;
                interface IUniswapV3Pool {
                    /// @notice Swap token0 for token1, or token1 for token0
                    /// @dev The caller of this method receives a callback in the form of IUniswapV3SwapCallback#uniswapV3SwapCallback
                    /// @param recipient The address to receive the output of the swap
                    /// @param zeroForOne The direction of the swap, true for token0 to token1, false for token1 to token0
                    /// @param amountSpecified The amount of the swap, which implicitly configures the swap as exact input (positive),
                    /// or exact output (negative)
                    /// @param sqrtPriceLimitX96 The Q64.96 sqrt price limit. If zero for one, the price cannot be less than this
                    /// value after the swap. If one for zero, the price cannot be greater than this value after the swap
                    /// @param data Any data to be passed through to the callback
                    /// @return amount0 The delta of the balance of token0 of the pool, exact when negative, minimum when positive
                    /// @return amount1 The delta of the balance of token1 of the pool, exact when negative, minimum when positive
                    function swap(
                        address recipient,
                        bool zeroForOne,
                        int256 amountSpecified,
                        uint160 sqrtPriceLimitX96,
                        bytes calldata data
                    ) external returns (int256 amount0, int256 amount1);
                }