ETH Price: $2,502.65 (+0.24%)

Transaction Decoder

Block:
20618778 at Aug-27-2024 08:39:11 AM +UTC
Transaction Fee:
0.00006920108747755 ETH $0.17
Gas Used:
54,775 Gas / 1.263369922 Gwei

Account State Difference:

  Address   Before After State Difference Code
(Fee Recipient: 0x4231...374)
758.654388524043223627 Eth758.654404197586410677 Eth0.00001567354318705
0x68715f1d...2dECFf15d
0.281235137983575705 Eth
Nonce: 64
0.281165936896098155 Eth
Nonce: 65
0.00006920108747755

Execution Trace

ApprovalProxy.transferAndMulticall( tokens=[0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48], amounts=[5363181], targets=[0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, 0xDef1C0ded9bec7F1a1670819833240f027b25EfF], datas=[CV6nswAAAAAAAAAAAAAAAN7xwN7ZvsfxoWcIGYMyQPAnsl7/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABR1e0=, gDuibQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABR1e0AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABwqn0AnQEgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACuguGmRxiGLNsHRnUounrDONgbrSAAB9MAqqjmyI/6NCg5cTyfq2Qg8dWzCAAAAAAAAAAAAAAAAAAAAAAAAAAAAhpWEzQAAAAAAAAAAAAAAAJTTJaazGue7ePQ/uX2kN8HD9C+WAAAAAAAAAAAAAAAAAAAAAAAAAABH9fibdK9n7ohpV3A=], values=[0, 0], refundTo=0xf70da97812CB96acDF810712Aa562db8dfA3dbEF )
  • FiatTokenProxy.23b872dd( )
    • FiatTokenV2_2.transferFrom( from=0x68715f1d1bdbbc620488a55AD0a8C382dECFf15d, to=0xA1BEa5fe917450041748Dbbbe7E9AC57A4bBEBaB, value=5363181 )
      transferAndMulticall[ApprovalProxy (ln:37)]
      File 1 of 3: 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 3: FiatTokenProxy
      pragma solidity ^0.4.24;
      
      // File: zos-lib/contracts/upgradeability/Proxy.sol
      
      /**
       * @title Proxy
       * @dev Implements delegation of calls to other contracts, with proper
       * forwarding of return values and bubbling of failures.
       * It defines a fallback function that delegates all calls to the address
       * returned by the abstract _implementation() internal function.
       */
      contract Proxy {
        /**
         * @dev Fallback function.
         * Implemented entirely in `_fallback`.
         */
        function () payable external {
          _fallback();
        }
      
        /**
         * @return The Address of the implementation.
         */
        function _implementation() internal view returns (address);
      
        /**
         * @dev Delegates execution to an implementation contract.
         * This is a low level function that doesn't return to its internal call site.
         * It will return to the external caller whatever the implementation returns.
         * @param implementation Address to delegate.
         */
        function _delegate(address implementation) internal {
          assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize)
      
            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
      
            // Copy the returned data.
            returndatacopy(0, 0, returndatasize)
      
            switch result
            // delegatecall returns 0 on error.
            case 0 { revert(0, returndatasize) }
            default { return(0, returndatasize) }
          }
        }
      
        /**
         * @dev Function that is run as the first thing in the fallback function.
         * Can be redefined in derived contracts to add functionality.
         * Redefinitions must call super._willFallback().
         */
        function _willFallback() internal {
        }
      
        /**
         * @dev fallback implementation.
         * Extracted to enable manual triggering.
         */
        function _fallback() internal {
          _willFallback();
          _delegate(_implementation());
        }
      }
      
      // File: openzeppelin-solidity/contracts/AddressUtils.sol
      
      /**
       * Utility library of inline functions on addresses
       */
      library AddressUtils {
      
        /**
         * Returns whether the target address is a contract
         * @dev This function will return false if invoked during the constructor of a contract,
         * as the code is not actually created until after the constructor finishes.
         * @param addr address to check
         * @return whether the target address is a contract
         */
        function isContract(address addr) internal view returns (bool) {
          uint256 size;
          // XXX Currently there is no better way to check if there is a contract in an address
          // than to check the size of the code at that address.
          // See https://ethereum.stackexchange.com/a/14016/36603
          // for more details about how this works.
          // TODO Check this again before the Serenity release, because all addresses will be
          // contracts then.
          // solium-disable-next-line security/no-inline-assembly
          assembly { size := extcodesize(addr) }
          return size > 0;
        }
      
      }
      
      // File: zos-lib/contracts/upgradeability/UpgradeabilityProxy.sol
      
      /**
       * @title UpgradeabilityProxy
       * @dev This contract implements a proxy that allows to change the
       * implementation address to which it will delegate.
       * Such a change is called an implementation upgrade.
       */
      contract UpgradeabilityProxy is Proxy {
        /**
         * @dev Emitted when the implementation is upgraded.
         * @param implementation Address of the new implementation.
         */
        event Upgraded(address implementation);
      
        /**
         * @dev Storage slot with the address of the current implementation.
         * This is the keccak-256 hash of "org.zeppelinos.proxy.implementation", and is
         * validated in the constructor.
         */
        bytes32 private constant IMPLEMENTATION_SLOT = 0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3;
      
        /**
         * @dev Contract constructor.
         * @param _implementation Address of the initial implementation.
         */
        constructor(address _implementation) public {
          assert(IMPLEMENTATION_SLOT == keccak256("org.zeppelinos.proxy.implementation"));
      
          _setImplementation(_implementation);
        }
      
        /**
         * @dev Returns the current implementation.
         * @return Address of the current implementation
         */
        function _implementation() internal view returns (address impl) {
          bytes32 slot = IMPLEMENTATION_SLOT;
          assembly {
            impl := sload(slot)
          }
        }
      
        /**
         * @dev Upgrades the proxy to a new implementation.
         * @param newImplementation Address of the new implementation.
         */
        function _upgradeTo(address newImplementation) internal {
          _setImplementation(newImplementation);
          emit Upgraded(newImplementation);
        }
      
        /**
         * @dev Sets the implementation address of the proxy.
         * @param newImplementation Address of the new implementation.
         */
        function _setImplementation(address newImplementation) private {
          require(AddressUtils.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
      
          bytes32 slot = IMPLEMENTATION_SLOT;
      
          assembly {
            sstore(slot, newImplementation)
          }
        }
      }
      
      // File: zos-lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol
      
      /**
       * @title AdminUpgradeabilityProxy
       * @dev This contract combines an upgradeability proxy with an authorization
       * mechanism for administrative tasks.
       * All external functions in this contract must be guarded by the
       * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
       * feature proposal that would enable this to be done automatically.
       */
      contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
        /**
         * @dev Emitted when the administration has been transferred.
         * @param previousAdmin Address of the previous admin.
         * @param newAdmin Address of the new admin.
         */
        event AdminChanged(address previousAdmin, address newAdmin);
      
        /**
         * @dev Storage slot with the admin of the contract.
         * This is the keccak-256 hash of "org.zeppelinos.proxy.admin", and is
         * validated in the constructor.
         */
        bytes32 private constant ADMIN_SLOT = 0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b;
      
        /**
         * @dev Modifier to check whether the `msg.sender` is the admin.
         * If it is, it will run the function. Otherwise, it will delegate the call
         * to the implementation.
         */
        modifier ifAdmin() {
          if (msg.sender == _admin()) {
            _;
          } else {
            _fallback();
          }
        }
      
        /**
         * Contract constructor.
         * It sets the `msg.sender` as the proxy administrator.
         * @param _implementation address of the initial implementation.
         */
        constructor(address _implementation) UpgradeabilityProxy(_implementation) public {
          assert(ADMIN_SLOT == keccak256("org.zeppelinos.proxy.admin"));
      
          _setAdmin(msg.sender);
        }
      
        /**
         * @return The address of the proxy admin.
         */
        function admin() external view ifAdmin returns (address) {
          return _admin();
        }
      
        /**
         * @return The address of the implementation.
         */
        function implementation() external view ifAdmin returns (address) {
          return _implementation();
        }
      
        /**
         * @dev Changes the admin of the proxy.
         * Only the current admin can call this function.
         * @param newAdmin Address to transfer proxy administration to.
         */
        function changeAdmin(address newAdmin) external ifAdmin {
          require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
          emit AdminChanged(_admin(), newAdmin);
          _setAdmin(newAdmin);
        }
      
        /**
         * @dev Upgrade the backing implementation of the proxy.
         * Only the admin can call this function.
         * @param newImplementation Address of the new implementation.
         */
        function upgradeTo(address newImplementation) external ifAdmin {
          _upgradeTo(newImplementation);
        }
      
        /**
         * @dev Upgrade the backing implementation of the proxy and call a function
         * on the new implementation.
         * This is useful to initialize the proxied contract.
         * @param newImplementation Address of the new implementation.
         * @param data Data to send as msg.data in the low level call.
         * It should include the signature and the parameters of the function to be
         * called, as described in
         * https://solidity.readthedocs.io/en/develop/abi-spec.html#function-selector-and-argument-encoding.
         */
        function upgradeToAndCall(address newImplementation, bytes data) payable external ifAdmin {
          _upgradeTo(newImplementation);
          require(address(this).call.value(msg.value)(data));
        }
      
        /**
         * @return The admin slot.
         */
        function _admin() internal view returns (address adm) {
          bytes32 slot = ADMIN_SLOT;
          assembly {
            adm := sload(slot)
          }
        }
      
        /**
         * @dev Sets the address of the proxy admin.
         * @param newAdmin Address of the new proxy admin.
         */
        function _setAdmin(address newAdmin) internal {
          bytes32 slot = ADMIN_SLOT;
      
          assembly {
            sstore(slot, newAdmin)
          }
        }
      
        /**
         * @dev Only fall back when the sender is not the admin.
         */
        function _willFallback() internal {
          require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
          super._willFallback();
        }
      }
      
      // File: contracts/FiatTokenProxy.sol
      
      /**
      * Copyright CENTRE SECZ 2018
      *
      * Permission is hereby granted, free of charge, to any person obtaining a copy 
      * of this software and associated documentation files (the "Software"), to deal 
      * in the Software without restriction, including without limitation the rights 
      * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
      * copies of the Software, and to permit persons to whom the Software is furnished to 
      * do so, subject to the following conditions:
      *
      * The above copyright notice and this permission notice shall be included in all 
      * copies or substantial portions of the Software.
      *
      * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
      * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
      * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
      * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
      * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
      * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
      */
      
      pragma solidity ^0.4.24;
      
      
      /**
       * @title FiatTokenProxy
       * @dev This contract proxies FiatToken calls and enables FiatToken upgrades
      */ 
      contract FiatTokenProxy is AdminUpgradeabilityProxy {
          constructor(address _implementation) public AdminUpgradeabilityProxy(_implementation) {
          }
      }

      File 3 of 3: FiatTokenV2_2
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { EIP712Domain } from "./EIP712Domain.sol"; // solhint-disable-line no-unused-import
      import { Blacklistable } from "../v1/Blacklistable.sol"; // solhint-disable-line no-unused-import
      import { FiatTokenV1 } from "../v1/FiatTokenV1.sol"; // solhint-disable-line no-unused-import
      import { FiatTokenV2 } from "./FiatTokenV2.sol"; // solhint-disable-line no-unused-import
      import { FiatTokenV2_1 } from "./FiatTokenV2_1.sol";
      import { EIP712 } from "../util/EIP712.sol";
      // solhint-disable func-name-mixedcase
      /**
       * @title FiatToken V2.2
       * @notice ERC20 Token backed by fiat reserves, version 2.2
       */
      contract FiatTokenV2_2 is FiatTokenV2_1 {
          /**
           * @notice Initialize v2.2
           * @param accountsToBlacklist   A list of accounts to migrate from the old blacklist
           * @param newSymbol             New token symbol
           * data structure to the new blacklist data structure.
           */
          function initializeV2_2(
              address[] calldata accountsToBlacklist,
              string calldata newSymbol
          ) external {
              // solhint-disable-next-line reason-string
              require(_initializedVersion == 2);
              // Update fiat token symbol
              symbol = newSymbol;
              // Add previously blacklisted accounts to the new blacklist data structure
              // and remove them from the old blacklist data structure.
              for (uint256 i = 0; i < accountsToBlacklist.length; i++) {
                  require(
                      _deprecatedBlacklisted[accountsToBlacklist[i]],
                      "FiatTokenV2_2: Blacklisting previously unblacklisted account!"
                  );
                  _blacklist(accountsToBlacklist[i]);
                  delete _deprecatedBlacklisted[accountsToBlacklist[i]];
              }
              _blacklist(address(this));
              delete _deprecatedBlacklisted[address(this)];
              _initializedVersion = 3;
          }
          /**
           * @dev Internal function to get the current chain id.
           * @return The current chain id.
           */
          function _chainId() internal virtual view returns (uint256) {
              uint256 chainId;
              assembly {
                  chainId := chainid()
              }
              return chainId;
          }
          /**
           * @inheritdoc EIP712Domain
           */
          function _domainSeparator() internal override view returns (bytes32) {
              return EIP712.makeDomainSeparator(name, "2", _chainId());
          }
          /**
           * @notice Update allowance with a signed permit
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param owner       Token owner's address (Authorizer)
           * @param spender     Spender's address
           * @param value       Amount of allowance
           * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
           * @param signature   Signature bytes signed by an EOA wallet or a contract wallet
           */
          function permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              bytes memory signature
          ) external whenNotPaused {
              _permit(owner, spender, value, deadline, signature);
          }
          /**
           * @notice Execute a transfer with a signed authorization
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
           */
          function transferWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              bytes memory signature
          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
              _transferWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  signature
              );
          }
          /**
           * @notice Receive a transfer with a signed authorization from the payer
           * @dev This has an additional check to ensure that the payee's address
           * matches the caller of this function to prevent front-running attacks.
           * EOA wallet signatures should be packed in the order of r, s, v.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
           */
          function receiveWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              bytes memory signature
          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
              _receiveWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  signature
              );
          }
          /**
           * @notice Attempt to cancel an authorization
           * @dev Works only if the authorization is not yet used.
           * EOA wallet signatures should be packed in the order of r, s, v.
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
           */
          function cancelAuthorization(
              address authorizer,
              bytes32 nonce,
              bytes memory signature
          ) external whenNotPaused {
              _cancelAuthorization(authorizer, nonce, signature);
          }
          /**
           * @dev Helper method that sets the blacklist state of an account on balanceAndBlacklistStates.
           * If _shouldBlacklist is true, we apply a (1 << 255) bitmask with an OR operation on the
           * account's balanceAndBlacklistState. This flips the high bit for the account to 1,
           * indicating that the account is blacklisted.
           *
           * If _shouldBlacklist if false, we reset the account's balanceAndBlacklistStates to their
           * balances. This clears the high bit for the account, indicating that the account is unblacklisted.
           * @param _account         The address of the account.
           * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
           */
          function _setBlacklistState(address _account, bool _shouldBlacklist)
              internal
              override
          {
              balanceAndBlacklistStates[_account] = _shouldBlacklist
                  ? balanceAndBlacklistStates[_account] | (1 << 255)
                  : _balanceOf(_account);
          }
          /**
           * @dev Helper method that sets the balance of an account on balanceAndBlacklistStates.
           * Since balances are stored in the last 255 bits of the balanceAndBlacklistStates value,
           * we need to ensure that the updated balance does not exceed (2^255 - 1).
           * Since blacklisted accounts' balances cannot be updated, the method will also
           * revert if the account is blacklisted
           * @param _account The address of the account.
           * @param _balance The new fiat token balance of the account (max: (2^255 - 1)).
           */
          function _setBalance(address _account, uint256 _balance) internal override {
              require(
                  _balance <= ((1 << 255) - 1),
                  "FiatTokenV2_2: Balance exceeds (2^255 - 1)"
              );
              require(
                  !_isBlacklisted(_account),
                  "FiatTokenV2_2: Account is blacklisted"
              );
              balanceAndBlacklistStates[_account] = _balance;
          }
          /**
           * @inheritdoc Blacklistable
           */
          function _isBlacklisted(address _account)
              internal
              override
              view
              returns (bool)
          {
              return balanceAndBlacklistStates[_account] >> 255 == 1;
          }
          /**
           * @dev Helper method to obtain the balance of an account. Since balances
           * are stored in the last 255 bits of the balanceAndBlacklistStates value,
           * we apply a ((1 << 255) - 1) bit bitmask with an AND operation on the
           * balanceAndBlacklistState to obtain the balance.
           * @param _account  The address of the account.
           * @return          The fiat token balance of the account.
           */
          function _balanceOf(address _account)
              internal
              override
              view
              returns (uint256)
          {
              return balanceAndBlacklistStates[_account] & ((1 << 255) - 1);
          }
          /**
           * @inheritdoc FiatTokenV1
           */
          function approve(address spender, uint256 value)
              external
              override
              whenNotPaused
              returns (bool)
          {
              _approve(msg.sender, spender, value);
              return true;
          }
          /**
           * @inheritdoc FiatTokenV2
           */
          function permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) external override whenNotPaused {
              _permit(owner, spender, value, deadline, v, r, s);
          }
          /**
           * @inheritdoc FiatTokenV2
           */
          function increaseAllowance(address spender, uint256 increment)
              external
              override
              whenNotPaused
              returns (bool)
          {
              _increaseAllowance(msg.sender, spender, increment);
              return true;
          }
          /**
           * @inheritdoc FiatTokenV2
           */
          function decreaseAllowance(address spender, uint256 decrement)
              external
              override
              whenNotPaused
              returns (bool)
          {
              _decreaseAllowance(msg.sender, spender, decrement);
              return true;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.2 <0.8.0;
      /**
       * @dev Collection of functions related to the address type
       */
      library Address {
          /**
           * @dev Returns true if `account` is a contract.
           *
           * [IMPORTANT]
           * ====
           * It is unsafe to assume that an address for which this function returns
           * false is an externally-owned account (EOA) and not a contract.
           *
           * Among others, `isContract` will return false for the following
           * types of addresses:
           *
           *  - an externally-owned account
           *  - a contract in construction
           *  - an address where a contract will be created
           *  - an address where a contract lived, but was destroyed
           * ====
           */
          function isContract(address account) internal view returns (bool) {
              // This method relies on extcodesize, which returns 0 for contracts in
              // construction, since the code is only stored at the end of the
              // constructor execution.
              uint256 size;
              // solhint-disable-next-line no-inline-assembly
              assembly { size := extcodesize(account) }
              return size > 0;
          }
          /**
           * @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://diligence.consensys.net/posts/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/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
           */
          function sendValue(address payable recipient, uint256 amount) internal {
              require(address(this).balance >= amount, "Address: insufficient balance");
              // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
              (bool success, ) = recipient.call{ value: amount }("");
              require(success, "Address: unable to send value, recipient may have reverted");
          }
          /**
           * @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, it is bubbled up by this
           * function (like regular Solidity function calls).
           *
           * 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.
           *
           * _Available since v3.1._
           */
          function functionCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionCall(target, data, "Address: low-level call failed");
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
           * `errorMessage` as a fallback revert reason when `target` reverts.
           *
           * _Available since v3.1._
           */
          function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
              return functionCallWithValue(target, data, 0, errorMessage);
          }
          /**
           * @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`.
           *
           * _Available since v3.1._
           */
          function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
              return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
          }
          /**
           * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
           * with `errorMessage` as a fallback revert reason when `target` reverts.
           *
           * _Available since v3.1._
           */
          function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
              require(address(this).balance >= value, "Address: insufficient balance for call");
              require(isContract(target), "Address: call to non-contract");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.call{ value: value }(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but performing a static call.
           *
           * _Available since v3.3._
           */
          function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
              return functionStaticCall(target, data, "Address: low-level static call failed");
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
           * but performing a static call.
           *
           * _Available since v3.3._
           */
          function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
              require(isContract(target), "Address: static call to non-contract");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.staticcall(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but performing a delegate call.
           *
           * _Available since v3.4._
           */
          function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionDelegateCall(target, data, "Address: low-level delegate call failed");
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
           * but performing a delegate call.
           *
           * _Available since v3.4._
           */
          function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
              require(isContract(target), "Address: delegate call to non-contract");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.delegatecall(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
              if (success) {
                  return returndata;
              } else {
                  // 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
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let returndata_size := mload(returndata)
                          revert(add(32, returndata), returndata_size)
                      }
                  } else {
                      revert(errorMessage);
                  }
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      import "./IERC20.sol";
      import "../../math/SafeMath.sol";
      import "../../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 SafeMath for uint256;
          using Address for address;
          function safeTransfer(IERC20 token, address to, uint256 value) internal {
              _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
          }
          function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
              _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
          }
          /**
           * @dev Deprecated. This function has issues similar to the ones found in
           * {IERC20-approve}, and its usage is discouraged.
           *
           * Whenever possible, use {safeIncreaseAllowance} and
           * {safeDecreaseAllowance} instead.
           */
          function safeApprove(IERC20 token, address spender, uint256 value) internal {
              // safeApprove should only be called when setting an initial allowance,
              // or when resetting it to zero. To increase and decrease it, use
              // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
              // solhint-disable-next-line max-line-length
              require((value == 0) || (token.allowance(address(this), spender) == 0),
                  "SafeERC20: approve from non-zero to non-zero allowance"
              );
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
          }
          function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
              uint256 newAllowance = token.allowance(address(this), spender).add(value);
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
          }
          function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
              uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
          }
          /**
           * @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, "SafeERC20: low-level call failed");
              if (returndata.length > 0) { // Return data is optional
                  // solhint-disable-next-line max-line-length
                  require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      /**
       * @dev Interface of the ERC20 standard as defined in the EIP.
       */
      interface IERC20 {
          /**
           * @dev Returns the amount of tokens in existence.
           */
          function totalSupply() external view returns (uint256);
          /**
           * @dev Returns the amount of tokens owned by `account`.
           */
          function balanceOf(address account) external view returns (uint256);
          /**
           * @dev Moves `amount` tokens from the caller's account to `recipient`.
           *
           * Returns a boolean value indicating whether the operation succeeded.
           *
           * Emits a {Transfer} event.
           */
          function transfer(address recipient, uint256 amount) 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 `amount` 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 amount) external returns (bool);
          /**
           * @dev Moves `amount` tokens from `sender` to `recipient` using the
           * allowance mechanism. `amount` is then deducted from the caller's
           * allowance.
           *
           * Returns a boolean value indicating whether the operation succeeded.
           *
           * Emits a {Transfer} event.
           */
          function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
          /**
           * @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);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      /**
       * @dev Wrappers over Solidity's arithmetic operations with added overflow
       * checks.
       *
       * Arithmetic operations in Solidity wrap on overflow. This can easily result
       * in bugs, because programmers usually assume that an overflow raises an
       * error, which is the standard behavior in high level programming languages.
       * `SafeMath` restores this intuition by reverting the transaction when an
       * operation overflows.
       *
       * Using this library instead of the unchecked operations eliminates an entire
       * class of bugs, so it's recommended to use it always.
       */
      library SafeMath {
          /**
           * @dev Returns the addition of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              uint256 c = a + b;
              if (c < a) return (false, 0);
              return (true, c);
          }
          /**
           * @dev Returns the substraction of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b > a) return (false, 0);
              return (true, a - b);
          }
          /**
           * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
              // benefit is lost if 'b' is also tested.
              // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
              if (a == 0) return (true, 0);
              uint256 c = a * b;
              if (c / a != b) return (false, 0);
              return (true, c);
          }
          /**
           * @dev Returns the division of two unsigned integers, with a division by zero flag.
           *
           * _Available since v3.4._
           */
          function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b == 0) return (false, 0);
              return (true, a / b);
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
           *
           * _Available since v3.4._
           */
          function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b == 0) return (false, 0);
              return (true, a % b);
          }
          /**
           * @dev Returns the addition of two unsigned integers, reverting on
           * overflow.
           *
           * Counterpart to Solidity's `+` operator.
           *
           * Requirements:
           *
           * - Addition cannot overflow.
           */
          function add(uint256 a, uint256 b) internal pure returns (uint256) {
              uint256 c = a + b;
              require(c >= a, "SafeMath: addition overflow");
              return c;
          }
          /**
           * @dev Returns the subtraction of two unsigned integers, reverting on
           * overflow (when the result is negative).
           *
           * Counterpart to Solidity's `-` operator.
           *
           * Requirements:
           *
           * - Subtraction cannot overflow.
           */
          function sub(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b <= a, "SafeMath: subtraction overflow");
              return a - b;
          }
          /**
           * @dev Returns the multiplication of two unsigned integers, reverting on
           * overflow.
           *
           * Counterpart to Solidity's `*` operator.
           *
           * Requirements:
           *
           * - Multiplication cannot overflow.
           */
          function mul(uint256 a, uint256 b) internal pure returns (uint256) {
              if (a == 0) return 0;
              uint256 c = a * b;
              require(c / a == b, "SafeMath: multiplication overflow");
              return c;
          }
          /**
           * @dev Returns the integer division of two unsigned integers, reverting on
           * division by zero. The result is rounded towards zero.
           *
           * Counterpart to Solidity's `/` operator. Note: this function uses a
           * `revert` opcode (which leaves remaining gas untouched) while Solidity
           * uses an invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function div(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b > 0, "SafeMath: division by zero");
              return a / b;
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
           * reverting when dividing by zero.
           *
           * Counterpart to Solidity's `%` operator. This function uses a `revert`
           * opcode (which leaves remaining gas untouched) while Solidity uses an
           * invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function mod(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b > 0, "SafeMath: modulo by zero");
              return a % b;
          }
          /**
           * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
           * overflow (when the result is negative).
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {trySub}.
           *
           * Counterpart to Solidity's `-` operator.
           *
           * Requirements:
           *
           * - Subtraction cannot overflow.
           */
          function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b <= a, errorMessage);
              return a - b;
          }
          /**
           * @dev Returns the integer division of two unsigned integers, reverting with custom message on
           * division by zero. The result is rounded towards zero.
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {tryDiv}.
           *
           * Counterpart to Solidity's `/` operator. Note: this function uses a
           * `revert` opcode (which leaves remaining gas untouched) while Solidity
           * uses an invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b > 0, errorMessage);
              return a / b;
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
           * reverting with custom message when dividing by zero.
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {tryMod}.
           *
           * Counterpart to Solidity's `%` operator. This function uses a `revert`
           * opcode (which leaves remaining gas untouched) while Solidity uses an
           * invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b > 0, errorMessage);
              return a % b;
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { FiatTokenV2 } from "./FiatTokenV2.sol";
      // solhint-disable func-name-mixedcase
      /**
       * @title FiatToken V2.1
       * @notice ERC20 Token backed by fiat reserves, version 2.1
       */
      contract FiatTokenV2_1 is FiatTokenV2 {
          /**
           * @notice Initialize v2.1
           * @param lostAndFound  The address to which the locked funds are sent
           */
          function initializeV2_1(address lostAndFound) external {
              // solhint-disable-next-line reason-string
              require(_initializedVersion == 1);
              uint256 lockedAmount = _balanceOf(address(this));
              if (lockedAmount > 0) {
                  _transfer(address(this), lostAndFound, lockedAmount);
              }
              _blacklist(address(this));
              _initializedVersion = 2;
          }
          /**
           * @notice Version string for the EIP712 domain separator
           * @return Version string
           */
          function version() external pure returns (string memory) {
              return "2";
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { FiatTokenV1_1 } from "../v1.1/FiatTokenV1_1.sol";
      import { EIP712 } from "../util/EIP712.sol";
      import { EIP3009 } from "./EIP3009.sol";
      import { EIP2612 } from "./EIP2612.sol";
      /**
       * @title FiatToken V2
       * @notice ERC20 Token backed by fiat reserves, version 2
       */
      contract FiatTokenV2 is FiatTokenV1_1, EIP3009, EIP2612 {
          uint8 internal _initializedVersion;
          /**
           * @notice Initialize v2
           * @param newName   New token name
           */
          function initializeV2(string calldata newName) external {
              // solhint-disable-next-line reason-string
              require(initialized && _initializedVersion == 0);
              name = newName;
              _DEPRECATED_CACHED_DOMAIN_SEPARATOR = EIP712.makeDomainSeparator(
                  newName,
                  "2"
              );
              _initializedVersion = 1;
          }
          /**
           * @notice Increase the allowance by a given increment
           * @param spender   Spender's address
           * @param increment Amount of increase in allowance
           * @return True if successful
           */
          function increaseAllowance(address spender, uint256 increment)
              external
              virtual
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(spender)
              returns (bool)
          {
              _increaseAllowance(msg.sender, spender, increment);
              return true;
          }
          /**
           * @notice Decrease the allowance by a given decrement
           * @param spender   Spender's address
           * @param decrement Amount of decrease in allowance
           * @return True if successful
           */
          function decreaseAllowance(address spender, uint256 decrement)
              external
              virtual
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(spender)
              returns (bool)
          {
              _decreaseAllowance(msg.sender, spender, decrement);
              return true;
          }
          /**
           * @notice Execute a transfer with a signed authorization
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function transferWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
              _transferWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  v,
                  r,
                  s
              );
          }
          /**
           * @notice Receive a transfer with a signed authorization from the payer
           * @dev This has an additional check to ensure that the payee's address
           * matches the caller of this function to prevent front-running attacks.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function receiveWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
              _receiveWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  v,
                  r,
                  s
              );
          }
          /**
           * @notice Attempt to cancel an authorization
           * @dev Works only if the authorization is not yet used.
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function cancelAuthorization(
              address authorizer,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) external whenNotPaused {
              _cancelAuthorization(authorizer, nonce, v, r, s);
          }
          /**
           * @notice Update allowance with a signed permit
           * @param owner       Token owner's address (Authorizer)
           * @param spender     Spender's address
           * @param value       Amount of allowance
           * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
           * @param v           v of the signature
           * @param r           r of the signature
           * @param s           s of the signature
           */
          function permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              uint8 v,
              bytes32 r,
              bytes32 s
          )
              external
              virtual
              whenNotPaused
              notBlacklisted(owner)
              notBlacklisted(spender)
          {
              _permit(owner, spender, value, deadline, v, r, s);
          }
          /**
           * @dev Internal function to increase the allowance by a given increment
           * @param owner     Token owner's address
           * @param spender   Spender's address
           * @param increment Amount of increase
           */
          function _increaseAllowance(
              address owner,
              address spender,
              uint256 increment
          ) internal override {
              _approve(owner, spender, allowed[owner][spender].add(increment));
          }
          /**
           * @dev Internal function to decrease the allowance by a given decrement
           * @param owner     Token owner's address
           * @param spender   Spender's address
           * @param decrement Amount of decrease
           */
          function _decreaseAllowance(
              address owner,
              address spender,
              uint256 decrement
          ) internal override {
              _approve(
                  owner,
                  spender,
                  allowed[owner][spender].sub(
                      decrement,
                      "ERC20: decreased allowance below zero"
                  )
              );
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      // solhint-disable func-name-mixedcase
      /**
       * @title EIP712 Domain
       */
      contract EIP712Domain {
          // was originally DOMAIN_SEPARATOR
          // but that has been moved to a method so we can override it in V2_2+
          bytes32 internal _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
          /**
           * @notice Get the EIP712 Domain Separator.
           * @return The bytes32 EIP712 domain separator.
           */
          function DOMAIN_SEPARATOR() external view returns (bytes32) {
              return _domainSeparator();
          }
          /**
           * @dev Internal method to get the EIP712 Domain Separator.
           * @return The bytes32 EIP712 domain separator.
           */
          function _domainSeparator() internal virtual view returns (bytes32) {
              return _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
      import { EIP712Domain } from "./EIP712Domain.sol";
      import { SignatureChecker } from "../util/SignatureChecker.sol";
      import { MessageHashUtils } from "../util/MessageHashUtils.sol";
      /**
       * @title EIP-3009
       * @notice Provide internal implementation for gas-abstracted transfers
       * @dev Contracts that inherit from this must wrap these with publicly
       * accessible functions, optionally adding modifiers where necessary
       */
      abstract contract EIP3009 is AbstractFiatTokenV2, EIP712Domain {
          // keccak256("TransferWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
          bytes32
              public constant TRANSFER_WITH_AUTHORIZATION_TYPEHASH = 0x7c7c6cdb67a18743f49ec6fa9b35f50d52ed05cbed4cc592e13b44501c1a2267;
          // keccak256("ReceiveWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
          bytes32
              public constant RECEIVE_WITH_AUTHORIZATION_TYPEHASH = 0xd099cc98ef71107a616c4f0f941f04c322d8e254fe26b3c6668db87aae413de8;
          // keccak256("CancelAuthorization(address authorizer,bytes32 nonce)")
          bytes32
              public constant CANCEL_AUTHORIZATION_TYPEHASH = 0x158b0a9edf7a828aad02f63cd515c68ef2f50ba807396f6d12842833a1597429;
          /**
           * @dev authorizer address => nonce => bool (true if nonce is used)
           */
          mapping(address => mapping(bytes32 => bool)) private _authorizationStates;
          event AuthorizationUsed(address indexed authorizer, bytes32 indexed nonce);
          event AuthorizationCanceled(
              address indexed authorizer,
              bytes32 indexed nonce
          );
          /**
           * @notice Returns the state of an authorization
           * @dev Nonces are randomly generated 32-byte data unique to the
           * authorizer's address
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @return True if the nonce is used
           */
          function authorizationState(address authorizer, bytes32 nonce)
              external
              view
              returns (bool)
          {
              return _authorizationStates[authorizer][nonce];
          }
          /**
           * @notice Execute a transfer with a signed authorization
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function _transferWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal {
              _transferWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  abi.encodePacked(r, s, v)
              );
          }
          /**
           * @notice Execute a transfer with a signed authorization
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
           */
          function _transferWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              bytes memory signature
          ) internal {
              _requireValidAuthorization(from, nonce, validAfter, validBefore);
              _requireValidSignature(
                  from,
                  keccak256(
                      abi.encode(
                          TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce
                      )
                  ),
                  signature
              );
              _markAuthorizationAsUsed(from, nonce);
              _transfer(from, to, value);
          }
          /**
           * @notice Receive a transfer with a signed authorization from the payer
           * @dev This has an additional check to ensure that the payee's address
           * matches the caller of this function to prevent front-running attacks.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function _receiveWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal {
              _receiveWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  abi.encodePacked(r, s, v)
              );
          }
          /**
           * @notice Receive a transfer with a signed authorization from the payer
           * @dev This has an additional check to ensure that the payee's address
           * matches the caller of this function to prevent front-running attacks.
           * EOA wallet signatures should be packed in the order of r, s, v.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
           */
          function _receiveWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              bytes memory signature
          ) internal {
              require(to == msg.sender, "FiatTokenV2: caller must be the payee");
              _requireValidAuthorization(from, nonce, validAfter, validBefore);
              _requireValidSignature(
                  from,
                  keccak256(
                      abi.encode(
                          RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce
                      )
                  ),
                  signature
              );
              _markAuthorizationAsUsed(from, nonce);
              _transfer(from, to, value);
          }
          /**
           * @notice Attempt to cancel an authorization
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function _cancelAuthorization(
              address authorizer,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal {
              _cancelAuthorization(authorizer, nonce, abi.encodePacked(r, s, v));
          }
          /**
           * @notice Attempt to cancel an authorization
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
           */
          function _cancelAuthorization(
              address authorizer,
              bytes32 nonce,
              bytes memory signature
          ) internal {
              _requireUnusedAuthorization(authorizer, nonce);
              _requireValidSignature(
                  authorizer,
                  keccak256(
                      abi.encode(CANCEL_AUTHORIZATION_TYPEHASH, authorizer, nonce)
                  ),
                  signature
              );
              _authorizationStates[authorizer][nonce] = true;
              emit AuthorizationCanceled(authorizer, nonce);
          }
          /**
           * @notice Validates that signature against input data struct
           * @param signer        Signer's address
           * @param dataHash      Hash of encoded data struct
           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
           */
          function _requireValidSignature(
              address signer,
              bytes32 dataHash,
              bytes memory signature
          ) private view {
              require(
                  SignatureChecker.isValidSignatureNow(
                      signer,
                      MessageHashUtils.toTypedDataHash(_domainSeparator(), dataHash),
                      signature
                  ),
                  "FiatTokenV2: invalid signature"
              );
          }
          /**
           * @notice Check that an authorization is unused
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           */
          function _requireUnusedAuthorization(address authorizer, bytes32 nonce)
              private
              view
          {
              require(
                  !_authorizationStates[authorizer][nonce],
                  "FiatTokenV2: authorization is used or canceled"
              );
          }
          /**
           * @notice Check that authorization is valid
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           */
          function _requireValidAuthorization(
              address authorizer,
              bytes32 nonce,
              uint256 validAfter,
              uint256 validBefore
          ) private view {
              require(
                  now > validAfter,
                  "FiatTokenV2: authorization is not yet valid"
              );
              require(now < validBefore, "FiatTokenV2: authorization is expired");
              _requireUnusedAuthorization(authorizer, nonce);
          }
          /**
           * @notice Mark an authorization as used
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           */
          function _markAuthorizationAsUsed(address authorizer, bytes32 nonce)
              private
          {
              _authorizationStates[authorizer][nonce] = true;
              emit AuthorizationUsed(authorizer, nonce);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
      import { EIP712Domain } from "./EIP712Domain.sol";
      import { MessageHashUtils } from "../util/MessageHashUtils.sol";
      import { SignatureChecker } from "../util/SignatureChecker.sol";
      /**
       * @title EIP-2612
       * @notice Provide internal implementation for gas-abstracted approvals
       */
      abstract contract EIP2612 is AbstractFiatTokenV2, EIP712Domain {
          // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
          bytes32
              public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
          mapping(address => uint256) private _permitNonces;
          /**
           * @notice Nonces for permit
           * @param owner Token owner's address (Authorizer)
           * @return Next nonce
           */
          function nonces(address owner) external view returns (uint256) {
              return _permitNonces[owner];
          }
          /**
           * @notice Verify a signed approval permit and execute if valid
           * @param owner     Token owner's address (Authorizer)
           * @param spender   Spender's address
           * @param value     Amount of allowance
           * @param deadline  The time at which the signature expires (unix time), or max uint256 value to signal no expiration
           * @param v         v of the signature
           * @param r         r of the signature
           * @param s         s of the signature
           */
          function _permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal {
              _permit(owner, spender, value, deadline, abi.encodePacked(r, s, v));
          }
          /**
           * @notice Verify a signed approval permit and execute if valid
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param owner      Token owner's address (Authorizer)
           * @param spender    Spender's address
           * @param value      Amount of allowance
           * @param deadline   The time at which the signature expires (unix time), or max uint256 value to signal no expiration
           * @param signature  Signature byte array signed by an EOA wallet or a contract wallet
           */
          function _permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              bytes memory signature
          ) internal {
              require(
                  deadline == type(uint256).max || deadline >= now,
                  "FiatTokenV2: permit is expired"
              );
              bytes32 typedDataHash = MessageHashUtils.toTypedDataHash(
                  _domainSeparator(),
                  keccak256(
                      abi.encode(
                          PERMIT_TYPEHASH,
                          owner,
                          spender,
                          value,
                          _permitNonces[owner]++,
                          deadline
                      )
                  )
              );
              require(
                  SignatureChecker.isValidSignatureNow(
                      owner,
                      typedDataHash,
                      signature
                  ),
                  "EIP2612: invalid signature"
              );
              _approve(owner, spender, value);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { AbstractFiatTokenV1 } from "../v1/AbstractFiatTokenV1.sol";
      abstract contract AbstractFiatTokenV2 is AbstractFiatTokenV1 {
          function _increaseAllowance(
              address owner,
              address spender,
              uint256 increment
          ) internal virtual;
          function _decreaseAllowance(
              address owner,
              address spender,
              uint256 decrement
          ) internal virtual;
      }
      /**
       * SPDX-License-Identifier: MIT
       *
       * Copyright (c) 2016 Smart Contract Solutions, Inc.
       * Copyright (c) 2018-2020 CENTRE SECZ
       *
       * Permission is hereby granted, free of charge, to any person obtaining a copy
       * of this software and associated documentation files (the "Software"), to deal
       * in the Software without restriction, including without limitation the rights
       * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
       * copies of the Software, and to permit persons to whom the Software is
       * furnished to do so, subject to the following conditions:
       *
       * The above copyright notice and this permission notice shall be included in
       * copies or substantial portions of the Software.
       *
       * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
       * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
       * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
       * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
       * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
       * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
       * SOFTWARE.
       */
      pragma solidity 0.6.12;
      import { Ownable } from "./Ownable.sol";
      /**
       * @notice Base contract which allows children to implement an emergency stop
       * mechanism
       * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/feb665136c0dae9912e08397c1a21c4af3651ef3/contracts/lifecycle/Pausable.sol
       * Modifications:
       * 1. Added pauser role, switched pause/unpause to be onlyPauser (6/14/2018)
       * 2. Removed whenNotPause/whenPaused from pause/unpause (6/14/2018)
       * 3. Removed whenPaused (6/14/2018)
       * 4. Switches ownable library to use ZeppelinOS (7/12/18)
       * 5. Remove constructor (7/13/18)
       * 6. Reformat, conform to Solidity 0.6 syntax and add error messages (5/13/20)
       * 7. Make public functions external (5/27/20)
       */
      contract Pausable is Ownable {
          event Pause();
          event Unpause();
          event PauserChanged(address indexed newAddress);
          address public pauser;
          bool public paused = false;
          /**
           * @dev Modifier to make a function callable only when the contract is not paused.
           */
          modifier whenNotPaused() {
              require(!paused, "Pausable: paused");
              _;
          }
          /**
           * @dev throws if called by any account other than the pauser
           */
          modifier onlyPauser() {
              require(msg.sender == pauser, "Pausable: caller is not the pauser");
              _;
          }
          /**
           * @dev called by the owner to pause, triggers stopped state
           */
          function pause() external onlyPauser {
              paused = true;
              emit Pause();
          }
          /**
           * @dev called by the owner to unpause, returns to normal state
           */
          function unpause() external onlyPauser {
              paused = false;
              emit Unpause();
          }
          /**
           * @notice Updates the pauser address.
           * @param _newPauser The address of the new pauser.
           */
          function updatePauser(address _newPauser) external onlyOwner {
              require(
                  _newPauser != address(0),
                  "Pausable: new pauser is the zero address"
              );
              pauser = _newPauser;
              emit PauserChanged(pauser);
          }
      }
      /**
       * SPDX-License-Identifier: MIT
       *
       * Copyright (c) 2018 zOS Global Limited.
       * Copyright (c) 2018-2020 CENTRE SECZ
       *
       * Permission is hereby granted, free of charge, to any person obtaining a copy
       * of this software and associated documentation files (the "Software"), to deal
       * in the Software without restriction, including without limitation the rights
       * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
       * copies of the Software, and to permit persons to whom the Software is
       * furnished to do so, subject to the following conditions:
       *
       * The above copyright notice and this permission notice shall be included in
       * copies or substantial portions of the Software.
       *
       * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
       * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
       * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
       * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
       * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
       * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
       * SOFTWARE.
       */
      pragma solidity 0.6.12;
      /**
       * @notice The Ownable contract has an owner address, and provides basic
       * authorization control functions
       * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-labs/blob/3887ab77b8adafba4a26ace002f3a684c1a3388b/upgradeability_ownership/contracts/ownership/Ownable.sol
       * Modifications:
       * 1. Consolidate OwnableStorage into this contract (7/13/18)
       * 2. Reformat, conform to Solidity 0.6 syntax, and add error messages (5/13/20)
       * 3. Make public functions external (5/27/20)
       */
      contract Ownable {
          // Owner of the contract
          address private _owner;
          /**
           * @dev Event to show ownership has been transferred
           * @param previousOwner representing the address of the previous owner
           * @param newOwner representing the address of the new owner
           */
          event OwnershipTransferred(address previousOwner, address newOwner);
          /**
           * @dev The constructor sets the original owner of the contract to the sender account.
           */
          constructor() public {
              setOwner(msg.sender);
          }
          /**
           * @dev Tells the address of the owner
           * @return the address of the owner
           */
          function owner() external view returns (address) {
              return _owner;
          }
          /**
           * @dev Sets a new owner address
           */
          function setOwner(address newOwner) internal {
              _owner = newOwner;
          }
          /**
           * @dev Throws if called by any account other than the owner.
           */
          modifier onlyOwner() {
              require(msg.sender == _owner, "Ownable: caller is not the owner");
              _;
          }
          /**
           * @dev Allows the current owner to transfer control of the contract to a newOwner.
           * @param newOwner The address to transfer ownership to.
           */
          function transferOwnership(address newOwner) external onlyOwner {
              require(
                  newOwner != address(0),
                  "Ownable: new owner is the zero address"
              );
              emit OwnershipTransferred(_owner, newOwner);
              setOwner(newOwner);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { SafeMath } from "@openzeppelin/contracts/math/SafeMath.sol";
      import { AbstractFiatTokenV1 } from "./AbstractFiatTokenV1.sol";
      import { Ownable } from "./Ownable.sol";
      import { Pausable } from "./Pausable.sol";
      import { Blacklistable } from "./Blacklistable.sol";
      /**
       * @title FiatToken
       * @dev ERC20 Token backed by fiat reserves
       */
      contract FiatTokenV1 is AbstractFiatTokenV1, Ownable, Pausable, Blacklistable {
          using SafeMath for uint256;
          string public name;
          string public symbol;
          uint8 public decimals;
          string public currency;
          address public masterMinter;
          bool internal initialized;
          /// @dev A mapping that stores the balance and blacklist states for a given address.
          /// The first bit defines whether the address is blacklisted (1 if blacklisted, 0 otherwise).
          /// The last 255 bits define the balance for the address.
          mapping(address => uint256) internal balanceAndBlacklistStates;
          mapping(address => mapping(address => uint256)) internal allowed;
          uint256 internal totalSupply_ = 0;
          mapping(address => bool) internal minters;
          mapping(address => uint256) internal minterAllowed;
          event Mint(address indexed minter, address indexed to, uint256 amount);
          event Burn(address indexed burner, uint256 amount);
          event MinterConfigured(address indexed minter, uint256 minterAllowedAmount);
          event MinterRemoved(address indexed oldMinter);
          event MasterMinterChanged(address indexed newMasterMinter);
          /**
           * @notice Initializes the fiat token contract.
           * @param tokenName       The name of the fiat token.
           * @param tokenSymbol     The symbol of the fiat token.
           * @param tokenCurrency   The fiat currency that the token represents.
           * @param tokenDecimals   The number of decimals that the token uses.
           * @param newMasterMinter The masterMinter address for the fiat token.
           * @param newPauser       The pauser address for the fiat token.
           * @param newBlacklister  The blacklister address for the fiat token.
           * @param newOwner        The owner of the fiat token.
           */
          function initialize(
              string memory tokenName,
              string memory tokenSymbol,
              string memory tokenCurrency,
              uint8 tokenDecimals,
              address newMasterMinter,
              address newPauser,
              address newBlacklister,
              address newOwner
          ) public {
              require(!initialized, "FiatToken: contract is already initialized");
              require(
                  newMasterMinter != address(0),
                  "FiatToken: new masterMinter is the zero address"
              );
              require(
                  newPauser != address(0),
                  "FiatToken: new pauser is the zero address"
              );
              require(
                  newBlacklister != address(0),
                  "FiatToken: new blacklister is the zero address"
              );
              require(
                  newOwner != address(0),
                  "FiatToken: new owner is the zero address"
              );
              name = tokenName;
              symbol = tokenSymbol;
              currency = tokenCurrency;
              decimals = tokenDecimals;
              masterMinter = newMasterMinter;
              pauser = newPauser;
              blacklister = newBlacklister;
              setOwner(newOwner);
              initialized = true;
          }
          /**
           * @dev Throws if called by any account other than a minter.
           */
          modifier onlyMinters() {
              require(minters[msg.sender], "FiatToken: caller is not a minter");
              _;
          }
          /**
           * @notice Mints fiat tokens to an address.
           * @param _to The address that will receive the minted tokens.
           * @param _amount The amount of tokens to mint. Must be less than or equal
           * to the minterAllowance of the caller.
           * @return True if the operation was successful.
           */
          function mint(address _to, uint256 _amount)
              external
              whenNotPaused
              onlyMinters
              notBlacklisted(msg.sender)
              notBlacklisted(_to)
              returns (bool)
          {
              require(_to != address(0), "FiatToken: mint to the zero address");
              require(_amount > 0, "FiatToken: mint amount not greater than 0");
              uint256 mintingAllowedAmount = minterAllowed[msg.sender];
              require(
                  _amount <= mintingAllowedAmount,
                  "FiatToken: mint amount exceeds minterAllowance"
              );
              totalSupply_ = totalSupply_.add(_amount);
              _setBalance(_to, _balanceOf(_to).add(_amount));
              minterAllowed[msg.sender] = mintingAllowedAmount.sub(_amount);
              emit Mint(msg.sender, _to, _amount);
              emit Transfer(address(0), _to, _amount);
              return true;
          }
          /**
           * @dev Throws if called by any account other than the masterMinter
           */
          modifier onlyMasterMinter() {
              require(
                  msg.sender == masterMinter,
                  "FiatToken: caller is not the masterMinter"
              );
              _;
          }
          /**
           * @notice Gets the minter allowance for an account.
           * @param minter The address to check.
           * @return The remaining minter allowance for the account.
           */
          function minterAllowance(address minter) external view returns (uint256) {
              return minterAllowed[minter];
          }
          /**
           * @notice Checks if an account is a minter.
           * @param account The address to check.
           * @return True if the account is a minter, false if the account is not a minter.
           */
          function isMinter(address account) external view returns (bool) {
              return minters[account];
          }
          /**
           * @notice Gets the remaining amount of fiat tokens a spender is allowed to transfer on
           * behalf of the token owner.
           * @param owner   The token owner's address.
           * @param spender The spender's address.
           * @return The remaining allowance.
           */
          function allowance(address owner, address spender)
              external
              override
              view
              returns (uint256)
          {
              return allowed[owner][spender];
          }
          /**
           * @notice Gets the totalSupply of the fiat token.
           * @return The totalSupply of the fiat token.
           */
          function totalSupply() external override view returns (uint256) {
              return totalSupply_;
          }
          /**
           * @notice Gets the fiat token balance of an account.
           * @param account  The address to check.
           * @return balance The fiat token balance of the account.
           */
          function balanceOf(address account)
              external
              override
              view
              returns (uint256)
          {
              return _balanceOf(account);
          }
          /**
           * @notice Sets a fiat token allowance for a spender to spend on behalf of the caller.
           * @param spender The spender's address.
           * @param value   The allowance amount.
           * @return True if the operation was successful.
           */
          function approve(address spender, uint256 value)
              external
              virtual
              override
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(spender)
              returns (bool)
          {
              _approve(msg.sender, spender, value);
              return true;
          }
          /**
           * @dev Internal function to set allowance.
           * @param owner     Token owner's address.
           * @param spender   Spender's address.
           * @param value     Allowance amount.
           */
          function _approve(
              address owner,
              address spender,
              uint256 value
          ) internal override {
              require(owner != address(0), "ERC20: approve from the zero address");
              require(spender != address(0), "ERC20: approve to the zero address");
              allowed[owner][spender] = value;
              emit Approval(owner, spender, value);
          }
          /**
           * @notice Transfers tokens from an address to another by spending the caller's allowance.
           * @dev The caller must have some fiat token allowance on the payer's tokens.
           * @param from  Payer's address.
           * @param to    Payee's address.
           * @param value Transfer amount.
           * @return True if the operation was successful.
           */
          function transferFrom(
              address from,
              address to,
              uint256 value
          )
              external
              override
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(from)
              notBlacklisted(to)
              returns (bool)
          {
              require(
                  value <= allowed[from][msg.sender],
                  "ERC20: transfer amount exceeds allowance"
              );
              _transfer(from, to, value);
              allowed[from][msg.sender] = allowed[from][msg.sender].sub(value);
              return true;
          }
          /**
           * @notice Transfers tokens from the caller.
           * @param to    Payee's address.
           * @param value Transfer amount.
           * @return True if the operation was successful.
           */
          function transfer(address to, uint256 value)
              external
              override
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(to)
              returns (bool)
          {
              _transfer(msg.sender, to, value);
              return true;
          }
          /**
           * @dev Internal function to process transfers.
           * @param from  Payer's address.
           * @param to    Payee's address.
           * @param value Transfer amount.
           */
          function _transfer(
              address from,
              address to,
              uint256 value
          ) internal override {
              require(from != address(0), "ERC20: transfer from the zero address");
              require(to != address(0), "ERC20: transfer to the zero address");
              require(
                  value <= _balanceOf(from),
                  "ERC20: transfer amount exceeds balance"
              );
              _setBalance(from, _balanceOf(from).sub(value));
              _setBalance(to, _balanceOf(to).add(value));
              emit Transfer(from, to, value);
          }
          /**
           * @notice Adds or updates a new minter with a mint allowance.
           * @param minter The address of the minter.
           * @param minterAllowedAmount The minting amount allowed for the minter.
           * @return True if the operation was successful.
           */
          function configureMinter(address minter, uint256 minterAllowedAmount)
              external
              whenNotPaused
              onlyMasterMinter
              returns (bool)
          {
              minters[minter] = true;
              minterAllowed[minter] = minterAllowedAmount;
              emit MinterConfigured(minter, minterAllowedAmount);
              return true;
          }
          /**
           * @notice Removes a minter.
           * @param minter The address of the minter to remove.
           * @return True if the operation was successful.
           */
          function removeMinter(address minter)
              external
              onlyMasterMinter
              returns (bool)
          {
              minters[minter] = false;
              minterAllowed[minter] = 0;
              emit MinterRemoved(minter);
              return true;
          }
          /**
           * @notice Allows a minter to burn some of its own tokens.
           * @dev The caller must be a minter, must not be blacklisted, and the amount to burn
           * should be less than or equal to the account's balance.
           * @param _amount the amount of tokens to be burned.
           */
          function burn(uint256 _amount)
              external
              whenNotPaused
              onlyMinters
              notBlacklisted(msg.sender)
          {
              uint256 balance = _balanceOf(msg.sender);
              require(_amount > 0, "FiatToken: burn amount not greater than 0");
              require(balance >= _amount, "FiatToken: burn amount exceeds balance");
              totalSupply_ = totalSupply_.sub(_amount);
              _setBalance(msg.sender, balance.sub(_amount));
              emit Burn(msg.sender, _amount);
              emit Transfer(msg.sender, address(0), _amount);
          }
          /**
           * @notice Updates the master minter address.
           * @param _newMasterMinter The address of the new master minter.
           */
          function updateMasterMinter(address _newMasterMinter) external onlyOwner {
              require(
                  _newMasterMinter != address(0),
                  "FiatToken: new masterMinter is the zero address"
              );
              masterMinter = _newMasterMinter;
              emit MasterMinterChanged(masterMinter);
          }
          /**
           * @inheritdoc Blacklistable
           */
          function _blacklist(address _account) internal override {
              _setBlacklistState(_account, true);
          }
          /**
           * @inheritdoc Blacklistable
           */
          function _unBlacklist(address _account) internal override {
              _setBlacklistState(_account, false);
          }
          /**
           * @dev Helper method that sets the blacklist state of an account.
           * @param _account         The address of the account.
           * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
           */
          function _setBlacklistState(address _account, bool _shouldBlacklist)
              internal
              virtual
          {
              _deprecatedBlacklisted[_account] = _shouldBlacklist;
          }
          /**
           * @dev Helper method that sets the balance of an account.
           * @param _account The address of the account.
           * @param _balance The new fiat token balance of the account.
           */
          function _setBalance(address _account, uint256 _balance) internal virtual {
              balanceAndBlacklistStates[_account] = _balance;
          }
          /**
           * @inheritdoc Blacklistable
           */
          function _isBlacklisted(address _account)
              internal
              virtual
              override
              view
              returns (bool)
          {
              return _deprecatedBlacklisted[_account];
          }
          /**
           * @dev Helper method to obtain the balance of an account.
           * @param _account  The address of the account.
           * @return          The fiat token balance of the account.
           */
          function _balanceOf(address _account)
              internal
              virtual
              view
              returns (uint256)
          {
              return balanceAndBlacklistStates[_account];
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { Ownable } from "./Ownable.sol";
      /**
       * @title Blacklistable Token
       * @dev Allows accounts to be blacklisted by a "blacklister" role
       */
      abstract contract Blacklistable is Ownable {
          address public blacklister;
          mapping(address => bool) internal _deprecatedBlacklisted;
          event Blacklisted(address indexed _account);
          event UnBlacklisted(address indexed _account);
          event BlacklisterChanged(address indexed newBlacklister);
          /**
           * @dev Throws if called by any account other than the blacklister.
           */
          modifier onlyBlacklister() {
              require(
                  msg.sender == blacklister,
                  "Blacklistable: caller is not the blacklister"
              );
              _;
          }
          /**
           * @dev Throws if argument account is blacklisted.
           * @param _account The address to check.
           */
          modifier notBlacklisted(address _account) {
              require(
                  !_isBlacklisted(_account),
                  "Blacklistable: account is blacklisted"
              );
              _;
          }
          /**
           * @notice Checks if account is blacklisted.
           * @param _account The address to check.
           * @return True if the account is blacklisted, false if the account is not blacklisted.
           */
          function isBlacklisted(address _account) external view returns (bool) {
              return _isBlacklisted(_account);
          }
          /**
           * @notice Adds account to blacklist.
           * @param _account The address to blacklist.
           */
          function blacklist(address _account) external onlyBlacklister {
              _blacklist(_account);
              emit Blacklisted(_account);
          }
          /**
           * @notice Removes account from blacklist.
           * @param _account The address to remove from the blacklist.
           */
          function unBlacklist(address _account) external onlyBlacklister {
              _unBlacklist(_account);
              emit UnBlacklisted(_account);
          }
          /**
           * @notice Updates the blacklister address.
           * @param _newBlacklister The address of the new blacklister.
           */
          function updateBlacklister(address _newBlacklister) external onlyOwner {
              require(
                  _newBlacklister != address(0),
                  "Blacklistable: new blacklister is the zero address"
              );
              blacklister = _newBlacklister;
              emit BlacklisterChanged(blacklister);
          }
          /**
           * @dev Checks if account is blacklisted.
           * @param _account The address to check.
           * @return true if the account is blacklisted, false otherwise.
           */
          function _isBlacklisted(address _account)
              internal
              virtual
              view
              returns (bool);
          /**
           * @dev Helper method that blacklists an account.
           * @param _account The address to blacklist.
           */
          function _blacklist(address _account) internal virtual;
          /**
           * @dev Helper method that unblacklists an account.
           * @param _account The address to unblacklist.
           */
          function _unBlacklist(address _account) internal virtual;
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
      abstract contract AbstractFiatTokenV1 is IERC20 {
          function _approve(
              address owner,
              address spender,
              uint256 value
          ) internal virtual;
          function _transfer(
              address from,
              address to,
              uint256 value
          ) internal virtual;
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { Ownable } from "../v1/Ownable.sol";
      import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
      import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
      contract Rescuable is Ownable {
          using SafeERC20 for IERC20;
          address private _rescuer;
          event RescuerChanged(address indexed newRescuer);
          /**
           * @notice Returns current rescuer
           * @return Rescuer's address
           */
          function rescuer() external view returns (address) {
              return _rescuer;
          }
          /**
           * @notice Revert if called by any account other than the rescuer.
           */
          modifier onlyRescuer() {
              require(msg.sender == _rescuer, "Rescuable: caller is not the rescuer");
              _;
          }
          /**
           * @notice Rescue ERC20 tokens locked up in this contract.
           * @param tokenContract ERC20 token contract address
           * @param to        Recipient address
           * @param amount    Amount to withdraw
           */
          function rescueERC20(
              IERC20 tokenContract,
              address to,
              uint256 amount
          ) external onlyRescuer {
              tokenContract.safeTransfer(to, amount);
          }
          /**
           * @notice Updates the rescuer address.
           * @param newRescuer The address of the new rescuer.
           */
          function updateRescuer(address newRescuer) external onlyOwner {
              require(
                  newRescuer != address(0),
                  "Rescuable: new rescuer is the zero address"
              );
              _rescuer = newRescuer;
              emit RescuerChanged(newRescuer);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { FiatTokenV1 } from "../v1/FiatTokenV1.sol";
      import { Rescuable } from "./Rescuable.sol";
      /**
       * @title FiatTokenV1_1
       * @dev ERC20 Token backed by fiat reserves
       */
      contract FiatTokenV1_1 is FiatTokenV1, Rescuable {
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      import { ECRecover } from "./ECRecover.sol";
      import { IERC1271 } from "../interface/IERC1271.sol";
      /**
       * @dev Signature verification helper that can be used instead of `ECRecover.recover` to seamlessly support both ECDSA
       * signatures from externally owned accounts (EOAs) as well as ERC1271 signatures from smart contract wallets.
       *
       * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/SignatureChecker.sol
       */
      library SignatureChecker {
          /**
           * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
           * signature is validated against that smart contract using ERC1271, otherwise it's validated using `ECRecover.recover`.
           * @param signer        Address of the claimed signer
           * @param digest        Keccak-256 hash digest of the signed message
           * @param signature     Signature byte array associated with hash
           */
          function isValidSignatureNow(
              address signer,
              bytes32 digest,
              bytes memory signature
          ) external view returns (bool) {
              if (!isContract(signer)) {
                  return ECRecover.recover(digest, signature) == signer;
              }
              return isValidERC1271SignatureNow(signer, digest, signature);
          }
          /**
           * @dev Checks if a signature is valid for a given signer and data hash. The signature is validated
           * against the signer smart contract using ERC1271.
           * @param signer        Address of the claimed signer
           * @param digest        Keccak-256 hash digest of the signed message
           * @param signature     Signature byte array associated with hash
           *
           * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
           * change through time. It could return true at block N and false at block N+1 (or the opposite).
           */
          function isValidERC1271SignatureNow(
              address signer,
              bytes32 digest,
              bytes memory signature
          ) internal view returns (bool) {
              (bool success, bytes memory result) = signer.staticcall(
                  abi.encodeWithSelector(
                      IERC1271.isValidSignature.selector,
                      digest,
                      signature
                  )
              );
              return (success &&
                  result.length >= 32 &&
                  abi.decode(result, (bytes32)) ==
                  bytes32(IERC1271.isValidSignature.selector));
          }
          /**
           * @dev Checks if the input address is a smart contract.
           */
          function isContract(address addr) internal view returns (bool) {
              uint256 size;
              assembly {
                  size := extcodesize(addr)
              }
              return size > 0;
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      /**
       * @dev Signature message hash utilities for producing digests to be consumed by {ECDSA} recovery or signing.
       *
       * The library provides methods for generating a hash of a message that conforms to the
       * https://eips.ethereum.org/EIPS/eip-191[EIP 191] and https://eips.ethereum.org/EIPS/eip-712[EIP 712]
       * specifications.
       */
      library MessageHashUtils {
          /**
           * @dev Returns the keccak256 digest of an EIP-712 typed data (EIP-191 version `0x01`).
           * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/MessageHashUtils.sol
           *
           * The digest is calculated from a `domainSeparator` and a `structHash`, by prefixing them with
           * `\\x19\\x01` and hashing the result. It corresponds to the hash signed by the
           * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`] JSON-RPC method as part of EIP-712.
           *
           * @param domainSeparator    Domain separator
           * @param structHash         Hashed EIP-712 data struct
           * @return digest            The keccak256 digest of an EIP-712 typed data
           */
          function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash)
              internal
              pure
              returns (bytes32 digest)
          {
              assembly {
                  let ptr := mload(0x40)
                  mstore(ptr, "\\x19\\x01")
                  mstore(add(ptr, 0x02), domainSeparator)
                  mstore(add(ptr, 0x22), structHash)
                  digest := keccak256(ptr, 0x42)
              }
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      /**
       * @title EIP712
       * @notice A library that provides EIP712 helper functions
       */
      library EIP712 {
          /**
           * @notice Make EIP712 domain separator
           * @param name      Contract name
           * @param version   Contract version
           * @param chainId   Blockchain ID
           * @return Domain separator
           */
          function makeDomainSeparator(
              string memory name,
              string memory version,
              uint256 chainId
          ) internal view returns (bytes32) {
              return
                  keccak256(
                      abi.encode(
                          // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                          0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                          keccak256(bytes(name)),
                          keccak256(bytes(version)),
                          chainId,
                          address(this)
                      )
                  );
          }
          /**
           * @notice Make EIP712 domain separator
           * @param name      Contract name
           * @param version   Contract version
           * @return Domain separator
           */
          function makeDomainSeparator(string memory name, string memory version)
              internal
              view
              returns (bytes32)
          {
              uint256 chainId;
              assembly {
                  chainId := chainid()
              }
              return makeDomainSeparator(name, version, chainId);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      /**
       * @title ECRecover
       * @notice A library that provides a safe ECDSA recovery function
       */
      library ECRecover {
          /**
           * @notice Recover signer's address from a signed message
           * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/65e4ffde586ec89af3b7e9140bdc9235d1254853/contracts/cryptography/ECDSA.sol
           * Modifications: Accept v, r, and s as separate arguments
           * @param digest    Keccak-256 hash digest of the signed message
           * @param v         v of the signature
           * @param r         r of the signature
           * @param s         s of the signature
           * @return Signer address
           */
          function recover(
              bytes32 digest,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal pure returns (address) {
              // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
              // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
              // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
              // signatures from current libraries generate a unique signature with an s-value in the lower half order.
              //
              // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
              // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
              // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
              // these malleable signatures as well.
              if (
                  uint256(s) >
                  0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0
              ) {
                  revert("ECRecover: invalid signature 's' value");
              }
              if (v != 27 && v != 28) {
                  revert("ECRecover: invalid signature 'v' value");
              }
              // If the signature is valid (and not malleable), return the signer address
              address signer = ecrecover(digest, v, r, s);
              require(signer != address(0), "ECRecover: invalid signature");
              return signer;
          }
          /**
           * @notice Recover signer's address from a signed message
           * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/0053ee040a7ff1dbc39691c9e67a69f564930a88/contracts/utils/cryptography/ECDSA.sol
           * @param digest    Keccak-256 hash digest of the signed message
           * @param signature Signature byte array associated with hash
           * @return Signer address
           */
          function recover(bytes32 digest, bytes memory signature)
              internal
              pure
              returns (address)
          {
              require(signature.length == 65, "ECRecover: invalid signature length");
              bytes32 r;
              bytes32 s;
              uint8 v;
              // ecrecover takes the signature parameters, and the only way to get them
              // currently is to use assembly.
              /// @solidity memory-safe-assembly
              assembly {
                  r := mload(add(signature, 0x20))
                  s := mload(add(signature, 0x40))
                  v := byte(0, mload(add(signature, 0x60)))
              }
              return recover(digest, v, r, s);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * 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;
      /**
       * @dev Interface of the ERC1271 standard signature validation method for
       * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
       */
      interface IERC1271 {
          /**
           * @dev Should return whether the signature provided is valid for the provided data
           * @param hash          Hash of the data to be signed
           * @param signature     Signature byte array associated with the provided data hash
           * @return magicValue   bytes4 magic value 0x1626ba7e when function passes
           */
          function isValidSignature(bytes32 hash, bytes memory signature)
              external
              view
              returns (bytes4 magicValue);
      }