ETH Price: $2,551.39 (+0.48%)

Transaction Decoder

Block:
16017306 at Nov-21-2022 08:50:35 AM +UTC
Transaction Fee:
0.00204136698819321 ETH $5.21
Gas Used:
185,210 Gas / 11.021904801 Gwei

Emitted Events:

105 Registry.ExecutionCompleted( middlewareID=0, bridgeID=18, inputAmount=20000000000000000 )
106 HopImpl.HopBridgeSend( integratorId=1 )
107 CanonicalTransactionChain.TransactionEnqueued( _l1TxOrigin=0x36BDE71C...4f7AB70B2, _target=0x42000000...000000007, _gasLimit=1920000, _data=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queueIndex=210273, _timestamp=1669020635 )
108 Lib_ResolvedDelegateProxy.0xcb0f7ffd78f9aee47a248fae8db181db6eee833039123e026dcbff529522e52a( 0xcb0f7ffd78f9aee47a248fae8db181db6eee833039123e026dcbff529522e52a, 0x00000000000000000000000083f6244bd87662118d96d9a6d44f09dfff14b30e, 00000000000000000000000064e5a143a3775a500bf19e609e1a74a5cbc3bb2a, 0000000000000000000000000000000000000000000000000000000000000080, 0000000000000000000000000000000000000000000000000000000000033561, 00000000000000000000000000000000000000000000000000000000001d4c00, 00000000000000000000000000000000000000000000000000000000000000c4, cc29a306000000000000000000000000058ace72bc4296c92b64034f2eacca98, 763c875500000000000000000000000000000000000000000000000000470de4, df8200000000000000000000000000000000000000000000000000000046b788, b9e7d6b100000000000000000000000000000000000000000000000000000184, 9973cb2d00000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000000 )
109 L1_ETH_Bridge.TransferSentToL2( chainId=10, recipient=[Sender] 0x058ace72bc4296c92b64034f2eacca98763c8755, amount=20000000000000000, amountOutMin=19905046232159921, deadline=1669021813549, relayer=0x00000000...000000000, relayerFee=0 )

Account State Difference:

  Address   Before After State Difference Code
0x058Ace72...8763c8755
0.063216260446898052 Eth
Nonce: 43
0.041174893458704842 Eth
Nonce: 44
0.02204136698819321
(MEV Builder: 0x473...dFc)
192.821072355471908353 Eth192.821350170471908353 Eth0.000277815
0x5E4e6592...0D24E9dD2
(Optimism: Canonical Transaction Chain)
0xb8901acB...02919727f
(Hop Protocol: Ethereum Bridge)
15,044.144358195475767984 Eth15,044.164358195475767984 Eth0.02

Execution Trace

ETH 0.02 Registry.outboundTransferTo( _userRequest=[{name:receiverAddress, type:address, order:1, indexed:false, value:0x058Ace72bc4296C92b64034F2eAccA98763c8755, valueString:0x058Ace72bc4296C92b64034F2eAccA98763c8755}, {name:toChainId, type:uint256, order:2, indexed:false, value:10, valueString:10}, {name:amount, type:uint256, order:3, indexed:false, value:20000000000000000, valueString:20000000000000000}, {name:middlewareRequest, type:tuple, order:4, indexed:false, value:[{name:id, type:uint256, order:1, indexed:false, value:0, valueString:0}, {name:optionalNativeAmount, type:uint256, order:2, indexed:false, value:0, valueString:0}, {name:inputToken, type:address, order:3, indexed:false, value:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, valueString:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE}, {name:data, type:bytes, order:4, indexed:false, value:0x, valueString:0x}], valueString:[{name:id, type:uint256, order:1, indexed:false, value:0, valueString:0}, {name:optionalNativeAmount, type:uint256, order:2, indexed:false, value:0, valueString:0}, {name:inputToken, type:address, order:3, indexed:false, value:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, valueString:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE}, {name:data, type:bytes, order:4, indexed:false, value:0x, valueString:0x}]}, {name:bridgeRequest, type:tuple, order:5, indexed:false, value:[{name:id, type:uint256, order:1, indexed:false, value:18, valueString:18}, {name:optionalNativeAmount, type:uint256, order:2, indexed:false, value:0, valueString:0}, {name:inputToken, type:address, order:3, indexed:false, value:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, valueString:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE}, {name:data, type:bytes, order:4, indexed:false, value:0x000000000000000000000000B8901ACB165ED027E32754E0FFE830802919727F00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000046B788B9E7D6B10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001849973CB2D0000000000000000000000000000000000000000000000000000000000000001, valueString:0x000000000000000000000000B8901ACB165ED027E32754E0FFE830802919727F00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000046B788B9E7D6B10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001849973CB2D0000000000000000000000000000000000000000000000000000000000000001}], valueString:[{name:id, type:uint256, order:1, indexed:false, value:18, valueString:18}, {name:optionalNativeAmount, type:uint256, order:2, indexed:false, value:0, valueString:0}, {name:inputToken, type:address, order:3, indexed:false, value:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, valueString:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE}, {name:data, type:bytes, order:4, indexed:false, value:0x000000000000000000000000B8901ACB165ED027E32754E0FFE830802919727F00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000046B788B9E7D6B10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001849973CB2D0000000000000000000000000000000000000000000000000000000000000001, valueString:0x000000000000000000000000B8901ACB165ED027E32754E0FFE830802919727F00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000046B788B9E7D6B10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001849973CB2D0000000000000000000000000000000000000000000000000000000000000001}]}] )
  • ETH 0.02 HopImpl.outboundTransferTo( _amount=20000000000000000, _from=0x058Ace72bc4296C92b64034F2eAccA98763c8755, _receiverAddress=0x058Ace72bc4296C92b64034F2eAccA98763c8755, _token=0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, _toChainId=10, _extraData=0x000000000000000000000000B8901ACB165ED027E32754E0FFE830802919727F00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000046B788B9E7D6B10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001849973CB2D0000000000000000000000000000000000000000000000000000000000000001 )
    • ETH 0.02 L1_ETH_Bridge.sendToL2( chainId=10, recipient=0x058Ace72bc4296C92b64034F2eAccA98763c8755, amount=20000000000000000, amountOutMin=19905046232159921, deadline=1669021813549, relayer=0x0000000000000000000000000000000000000000, relayerFee=0 )
      • OptimismMessengerWrapper.sendCrossDomainMessage( _calldata=0xCC29A306000000000000000000000000058ACE72BC4296C92B64034F2EACCA98763C875500000000000000000000000000000000000000000000000000470DE4DF8200000000000000000000000000000000000000000000000000000046B788B9E7D6B1000000000000000000000000000000000000000000000000000001849973CB2D00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 )
        • Lib_ResolvedDelegateProxy.3dbb202b( )
          • Lib_AddressManager.getAddress( _name=OVM_L1CrossDomainMessenger ) => ( 0xd9166833FF12A5F900ccfBf2c8B62a90F1Ca1FD5 )
          • L1CrossDomainMessenger.sendMessage( _target=0x83f6244Bd87662118d96D9a6D44f09dffF14b30E, _message=0xCC29A306000000000000000000000000058ACE72BC4296C92B64034F2EACCA98763C875500000000000000000000000000000000000000000000000000470DE4DF8200000000000000000000000000000000000000000000000000000046B788B9E7D6B1000000000000000000000000000000000000000000000000000001849973CB2D00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000, _gasLimit=1920000 )
            • Lib_AddressManager.getAddress( _name=CanonicalTransactionChain ) => ( 0x5E4e65926BA27467555EB562121fac00D24E9dD2 )
            • CanonicalTransactionChain.STATICCALL( )
            • CanonicalTransactionChain.enqueue( _target=0x4200000000000000000000000000000000000007, _gasLimit=1920000, _data=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
              outboundTransferTo[Registry (ln:107)]
              File 1 of 8: Registry
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.4;
              import "@openzeppelin/contracts/access/Ownable.sol";
              import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
              import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
              import "./helpers/errors.sol";
              import "./ImplBase.sol";
              import "./MiddlewareImplBase.sol";
              /**
              // @title Movr Regisrtry Contract.
              // @notice This is the main contract that is called using fund movr.
              // This contains all the bridge and middleware ids. 
              // RouteIds signify which bridge to be used. 
              // Middleware Id signifies which aggregator will be used for swapping if required. 
              */
              contract Registry is Ownable {
                  using SafeERC20 for IERC20;
                  address private constant NATIVE_TOKEN_ADDRESS =
                      address(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE);
                  ///@notice RouteData stores information for a route
                  struct RouteData {
                      address route;
                      bool isEnabled;
                      bool isMiddleware;
                  }
                  RouteData[] public routes;
                  modifier onlyExistingRoute(uint256 _routeId) {
                      require(
                          routes[_routeId].route != address(0),
                          MovrErrors.ROUTE_NOT_FOUND
                      );
                      _;
                  }
                  constructor(address _owner) Ownable() {
                      // first route is for direct bridging
                      routes.push(RouteData(NATIVE_TOKEN_ADDRESS, true, true));
                      transferOwnership(_owner);
                  }
                  // Function to receive Ether. msg.data must be empty
                  receive() external payable {}
                  //
                  // Events
                  //
                  event NewRouteAdded(
                      uint256 routeID,
                      address route,
                      bool isEnabled,
                      bool isMiddleware
                  );
                  event RouteDisabled(uint256 routeID);
                  event ExecutionCompleted(
                      uint256 middlewareID,
                      uint256 bridgeID,
                      uint256 inputAmount
                  );
                  /**
                  // @param id route id of middleware to be used
                  // @param optionalNativeAmount is the amount of native asset that the route requires 
                  // @param inputToken token address which will be swapped to
                  // BridgeRequest inputToken 
                  // @param data to be used by middleware
                  */
                  struct MiddlewareRequest {
                      uint256 id;
                      uint256 optionalNativeAmount;
                      address inputToken;
                      bytes data;
                  }
                  /**
                  // @param id route id of bridge to be used
                  // @param optionalNativeAmount optinal native amount, to be used
                  // when bridge needs native token along with ERC20    
                  // @param inputToken token addresss which will be bridged 
                  // @param data bridgeData to be used by bridge
                  */
                  struct BridgeRequest {
                      uint256 id;
                      uint256 optionalNativeAmount;
                      address inputToken;
                      bytes data;
                  }
                  /**
                  // @param receiverAddress Recipient address to recieve funds on destination chain
                  // @param toChainId Destination ChainId
                  // @param amount amount to be swapped if middlewareId is 0  it will be
                  // the amount to be bridged
                  // @param middlewareRequest middleware Requestdata
                  // @param bridgeRequest bridge request data
                  */
                  struct UserRequest {
                      address receiverAddress;
                      uint256 toChainId;
                      uint256 amount;
                      MiddlewareRequest middlewareRequest;
                      BridgeRequest bridgeRequest;
                  }
                  /**
                  // @notice function responsible for calling the respective implementation 
                  // depending on the bridge to be used
                  // If the middlewareId is 0 then no swap is required,
                  // we can directly bridge the source token to wherever required,
                  // else, we first call the Swap Impl Base for swapping to the required 
                  // token and then start the bridging
                  // @dev It is required for isMiddleWare to be true for route 0 as it is a special case
                  // @param _userRequest calldata follows the input data struct
                  */
                  function outboundTransferTo(UserRequest calldata _userRequest)
                      external
                      payable
                  {
                      require(_userRequest.amount != 0, MovrErrors.INVALID_AMT);
                      // make sure bridge ID is not 0
                      require(
                          _userRequest.bridgeRequest.id != 0,
                          MovrErrors.INVALID_BRIDGE_ID
                      );
                      // make sure bridge input is provided
                      require(
                          _userRequest.bridgeRequest.inputToken != address(0),
                          MovrErrors.ADDRESS_0_PROVIDED
                      );
                      // load middleware info and validate
                      RouteData memory middlewareInfo = routes[
                          _userRequest.middlewareRequest.id
                      ];
                      require(
                          middlewareInfo.route != address(0) &&
                              middlewareInfo.isEnabled &&
                              middlewareInfo.isMiddleware,
                          MovrErrors.ROUTE_NOT_ALLOWED
                      );
                      // load bridge info and validate
                      RouteData memory bridgeInfo = routes[_userRequest.bridgeRequest.id];
                      require(
                          bridgeInfo.route != address(0) &&
                              bridgeInfo.isEnabled &&
                              !bridgeInfo.isMiddleware,
                          MovrErrors.ROUTE_NOT_ALLOWED
                      );
                      emit ExecutionCompleted(
                          _userRequest.middlewareRequest.id,
                          _userRequest.bridgeRequest.id,
                          _userRequest.amount
                      );
                      // if middlewareID is 0 it means we dont want to perform a action before bridging
                      // and directly want to move for bridging
                      if (_userRequest.middlewareRequest.id == 0) {
                          // perform the bridging
                          ImplBase(bridgeInfo.route).outboundTransferTo{value: msg.value}(
                              _userRequest.amount,
                              msg.sender,
                              _userRequest.receiverAddress,
                              _userRequest.bridgeRequest.inputToken,
                              _userRequest.toChainId,
                              _userRequest.bridgeRequest.data
                          );
                          return;
                      }
                      // we first perform an action using the middleware
                      // we determine if the input asset is a native asset, if yes we pass
                      // the amount as value, else we pass the optionalNativeAmount
                      uint256 _amountOut = MiddlewareImplBase(middlewareInfo.route)
                          .performAction{
                          value: _userRequest.middlewareRequest.inputToken ==
                              NATIVE_TOKEN_ADDRESS
                              ? _userRequest.amount +
                                  _userRequest.middlewareRequest.optionalNativeAmount
                              : _userRequest.middlewareRequest.optionalNativeAmount
                      }(
                          msg.sender,
                          _userRequest.middlewareRequest.inputToken,
                          _userRequest.amount,
                          address(this),
                          _userRequest.middlewareRequest.data
                      );
                      // we mutate this variable if the input asset to bridge Impl is NATIVE
                      uint256 nativeInput = _userRequest.bridgeRequest.optionalNativeAmount;
                      // if the input asset is ERC20, we need to grant the bridge implementation approval
                      if (_userRequest.bridgeRequest.inputToken != NATIVE_TOKEN_ADDRESS) {
                          IERC20(_userRequest.bridgeRequest.inputToken).safeIncreaseAllowance(
                                  bridgeInfo.route,
                                  _amountOut
                              );
                      } else {
                          // if the input asset is native we need to set it as value
                          nativeInput =
                              _amountOut +
                              _userRequest.bridgeRequest.optionalNativeAmount;
                      }
                      // send off to bridge
                      ImplBase(bridgeInfo.route).outboundTransferTo{value: nativeInput}(
                          _amountOut,
                          address(this),
                          _userRequest.receiverAddress,
                          _userRequest.bridgeRequest.inputToken,
                          _userRequest.toChainId,
                          _userRequest.bridgeRequest.data
                      );
                  }
                  //
                  // Route management functions
                  //
                  /// @notice add routes to the registry.
                  function addRoutes(RouteData[] calldata _routes)
                      external
                      onlyOwner
                      returns (uint256[] memory)
                  {
                      require(_routes.length != 0, MovrErrors.EMPTY_INPUT);
                      uint256[] memory _routeIds = new uint256[](_routes.length);
                      for (uint256 i = 0; i < _routes.length; i++) {
                          require(
                              _routes[i].route != address(0),
                              MovrErrors.ADDRESS_0_PROVIDED
                          );
                          routes.push(_routes[i]);
                          _routeIds[i] = routes.length - 1;
                          emit NewRouteAdded(
                              i,
                              _routes[i].route,
                              _routes[i].isEnabled,
                              _routes[i].isMiddleware
                          );
                      }
                      return _routeIds;
                  }
                  ///@notice disables the route  if required.
                  function disableRoute(uint256 _routeId)
                      external
                      onlyOwner
                      onlyExistingRoute(_routeId)
                  {
                      routes[_routeId].isEnabled = false;
                      emit RouteDisabled(_routeId);
                  }
                  function rescueFunds(
                      address _token,
                      address _receiverAddress,
                      uint256 _amount
                  ) external onlyOwner {
                      IERC20(_token).safeTransfer(_receiverAddress, _amount);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "../utils/Context.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              abstract contract Ownable is Context {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  constructor () {
                      address msgSender = _msgSender();
                      _owner = msgSender;
                      emit OwnershipTransferred(address(0), msgSender);
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view virtual returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(owner() == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      emit OwnershipTransferred(_owner, address(0));
                      _owner = address(0);
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      emit OwnershipTransferred(_owner, newOwner);
                      _owner = newOwner;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^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 ^0.8.0;
              import "../IERC20.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 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) + value;
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                  }
                  function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                      unchecked {
                          uint256 oldAllowance = token.allowance(address(this), spender);
                          require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                          uint256 newAllowance = oldAllowance - value;
                          _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 >=0.8.0;
              library MovrErrors {
                  string internal constant ADDRESS_0_PROVIDED = "ADDRESS_0_PROVIDED";
                  string internal constant EMPTY_INPUT = "EMPTY_INPUT";
                  string internal constant LENGTH_MISMATCH = "LENGTH_MISMATCH";
                  string internal constant INVALID_VALUE = "INVALID_VALUE";
                  string internal constant INVALID_AMT = "INVALID_AMT";
                  string internal constant IMPL_NOT_FOUND = "IMPL_NOT_FOUND";
                  string internal constant ROUTE_NOT_FOUND = "ROUTE_NOT_FOUND";
                  string internal constant IMPL_NOT_ALLOWED = "IMPL_NOT_ALLOWED";
                  string internal constant ROUTE_NOT_ALLOWED = "ROUTE_NOT_ALLOWED";
                  string internal constant INVALID_CHAIN_DATA = "INVALID_CHAIN_DATA";
                  string internal constant CHAIN_NOT_SUPPORTED = "CHAIN_NOT_SUPPORTED";
                  string internal constant TOKEN_NOT_SUPPORTED = "TOKEN_NOT_SUPPORTED";
                  string internal constant NOT_IMPLEMENTED = "NOT_IMPLEMENTED";
                  string internal constant INVALID_SENDER = "INVALID_SENDER";
                  string internal constant INVALID_BRIDGE_ID = "INVALID_BRIDGE_ID";
                  string internal constant MIDDLEWARE_ACTION_FAILED =
                      "MIDDLEWARE_ACTION_FAILED";
                  string internal constant VALUE_SHOULD_BE_ZERO = "VALUE_SHOULD_BE_ZERO";
                  string internal constant VALUE_SHOULD_NOT_BE_ZERO = "VALUE_SHOULD_NOT_BE_ZERO";
                  string internal constant VALUE_NOT_ENOUGH = "VALUE_NOT_ENOUGH";
                  string internal constant VALUE_NOT_EQUAL_TO_AMOUNT = "VALUE_NOT_EQUAL_TO_AMOUNT";
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.4;
              import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
              import "@openzeppelin/contracts/access/Ownable.sol";
              import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
              import "./helpers/errors.sol";
              /**
              @title Abstract Implementation Contract.
              @notice All Bridge Implementation will follow this interface. 
              */
              abstract contract ImplBase is Ownable {
                  using SafeERC20 for IERC20;
                  address public registry;
                  address public constant NATIVE_TOKEN_ADDRESS =
                      address(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE);
                  event UpdateRegistryAddress(address indexed registryAddress);
                  constructor(address _registry) Ownable() {
                      registry = _registry;
                  }
                  modifier onlyRegistry() {
                      require(msg.sender == registry, MovrErrors.INVALID_SENDER);
                      _;
                  }
                  function updateRegistryAddress(address newRegistry) external onlyOwner {
                      registry = newRegistry;
                      emit UpdateRegistryAddress(newRegistry);
                  }
                  function rescueFunds(
                      address token,
                      address userAddress,
                      uint256 amount
                  ) external onlyOwner {
                      IERC20(token).safeTransfer(userAddress, amount);
                  }
                  function outboundTransferTo(
                      uint256 _amount,
                      address _from,
                      address _receiverAddress,
                      address _token,
                      uint256 _toChainId,
                      bytes memory _extraData
                  ) external payable virtual;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.4;
              import "@openzeppelin/contracts/access/Ownable.sol";
              import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
              import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
              import "./helpers/errors.sol";
              /**
              // @title Abstract Contract for middleware services.
              // @notice All middleware services will follow this interface. 
              */
              abstract contract MiddlewareImplBase is Ownable {
                  using SafeERC20 for IERC20;
                  address public immutable registry;
                  /// @notice only registry address is required.
                  constructor(address _registry) Ownable() {
                      registry = _registry;
                  }
                  modifier onlyRegistry {
                      require(msg.sender == registry, MovrErrors.INVALID_SENDER);
                      _;
                  }
                  function performAction(
                      address from,
                      address fromToken,
                      uint256 amount,
                      address receiverAddress,
                      bytes memory data
                  ) external payable virtual returns (uint256);
                  function rescueFunds(
                      address token,
                      address userAddress,
                      uint256 amount
                  ) external onlyOwner {
                      IERC20(token).safeTransfer(userAddress, amount);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              /*
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes calldata) {
                      this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                      return msg.data;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^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);
                          }
                      }
                  }
              }
              

              File 2 of 8: HopImpl
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.8.0;
              import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
              import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
              import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
              import "../../ImplBase.sol";
              import "../../helpers/errors.sol";
              import "../../interfaces/hop/IHopL1Bridge.sol";
              /**
              // @title Hop Protocol Implementation.
              // @notice This is the L1 implementation, so this is used when transferring from l1 to supported l2s
              //         Called by the registry if the selected bridge is HOP.
              // @dev Follows the interface of ImplBase.
              // @author Movr Network.
              */
              contract HopImpl is ImplBase, ReentrancyGuard {
                  using SafeERC20 for IERC20;
                  event HopBridgeSend(
                      uint256 indexed integratorId
                  );
                  // solhint-disable-next-line
                  constructor(address _registry) ImplBase(_registry) {}
                  struct HopExtraData {
                      address _l1bridgeAddr;
                      address _relayer;
                      uint256 _amountOutMin;
                      uint256 _relayerFee;
                      uint256 _deadline;
                      uint256 integratorId;
                  }
                  /**
                  // @notice Function responsible for cross chain transfers from L1 to L2. 
                  // @dev When calling the registry the allowance should be given to this contract, 
                  //      that is the implementation contract for HOP.
                  // @param _amount amount to be transferred to L2.
                  // @param _from userAddress or address from which the transfer was made.
                  // @param _receiverAddress address that will receive the funds on the destination chain.
                  // @param _token address of the token to be used for cross chain transfer.
                  // @param _toChainId chain Id for the destination chain 
                  // @param _extraData parameters required to call the hop function in bytes 
                  */
                  function outboundTransferTo(
                      uint256 _amount,
                      address _from,
                      address _receiverAddress,
                      address _token,
                      uint256 _toChainId,
                      bytes calldata _extraData
                  ) external payable override onlyRegistry nonReentrant {
                      // decode extra data
                      (
                          HopExtraData memory _hopExtraData
                      ) = abi.decode(
                              _extraData,
                              (HopExtraData)
                          );
                      emit HopBridgeSend(_hopExtraData.integratorId);
                      if (_token == NATIVE_TOKEN_ADDRESS) {
                          require(msg.value == _amount, MovrErrors.VALUE_NOT_EQUAL_TO_AMOUNT);
                          IHopL1Bridge(_hopExtraData._l1bridgeAddr).sendToL2{value: _amount}(
                              _toChainId,
                              _receiverAddress,
                              _amount,
                              _hopExtraData._amountOutMin,
                              _hopExtraData._deadline,
                              _hopExtraData._relayer,
                              _hopExtraData._relayerFee
                          );
                          return;
                      }
                      require(msg.value == 0, MovrErrors.VALUE_SHOULD_BE_ZERO);
                      IERC20(_token).safeTransferFrom(_from, address(this), _amount);
                      IERC20(_token).safeIncreaseAllowance(_hopExtraData._l1bridgeAddr, _amount);
                      // perform bridging
                      IHopL1Bridge(_hopExtraData._l1bridgeAddr).sendToL2(
                          _toChainId,
                          _receiverAddress,
                          _amount,
                          _hopExtraData._amountOutMin,
                          _hopExtraData._deadline,
                          _hopExtraData._relayer,
                          _hopExtraData._relayerFee
                      );
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
              pragma solidity ^0.8.0;
              /**
               * @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 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 `to`.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transfer(address to, 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 `from` to `to` 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 from,
                      address to,
                      uint256 amount
                  ) external returns (bool);
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
              pragma solidity ^0.8.0;
              import "../IERC20.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 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'
                      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) + value;
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                  }
                  function safeDecreaseAllowance(
                      IERC20 token,
                      address spender,
                      uint256 value
                  ) internal {
                      unchecked {
                          uint256 oldAllowance = token.allowance(address(this), spender);
                          require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                          uint256 newAllowance = oldAllowance - value;
                          _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
                          require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Contract module that helps prevent reentrant calls to a function.
               *
               * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
               * available, which can be applied to functions to make sure there are no nested
               * (reentrant) calls to them.
               *
               * Note that because there is a single `nonReentrant` guard, functions marked as
               * `nonReentrant` may not call one another. This can be worked around by making
               * those functions `private`, and then adding `external` `nonReentrant` entry
               * points to them.
               *
               * TIP: If you would like to learn more about reentrancy and alternative ways
               * to protect against it, check out our blog post
               * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
               */
              abstract contract ReentrancyGuard {
                  // Booleans are more expensive than uint256 or any type that takes up a full
                  // word because each write operation emits an extra SLOAD to first read the
                  // slot's contents, replace the bits taken up by the boolean, and then write
                  // back. This is the compiler's defense against contract upgrades and
                  // pointer aliasing, and it cannot be disabled.
                  // The values being non-zero value makes deployment a bit more expensive,
                  // but in exchange the refund on every call to nonReentrant will be lower in
                  // amount. Since refunds are capped to a percentage of the total
                  // transaction's gas, it is best to keep them low in cases like this one, to
                  // increase the likelihood of the full refund coming into effect.
                  uint256 private constant _NOT_ENTERED = 1;
                  uint256 private constant _ENTERED = 2;
                  uint256 private _status;
                  constructor() {
                      _status = _NOT_ENTERED;
                  }
                  /**
                   * @dev Prevents a contract from calling itself, directly or indirectly.
                   * Calling a `nonReentrant` function from another `nonReentrant`
                   * function is not supported. It is possible to prevent this from happening
                   * by making the `nonReentrant` function external, and making it call a
                   * `private` function that does the actual work.
                   */
                  modifier nonReentrant() {
                      // On the first call to nonReentrant, _notEntered will be true
                      require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                      // Any calls to nonReentrant after this point will fail
                      _status = _ENTERED;
                      _;
                      // By storing the original value once again, a refund is triggered (see
                      // https://eips.ethereum.org/EIPS/eip-2200)
                      _status = _NOT_ENTERED;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.4;
              import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
              import "@openzeppelin/contracts/access/Ownable.sol";
              import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
              import "./helpers/errors.sol";
              /**
              @title Abstract Implementation Contract.
              @notice All Bridge Implementation will follow this interface. 
              */
              abstract contract ImplBase is Ownable {
                  using SafeERC20 for IERC20;
                  address public registry;
                  address public constant NATIVE_TOKEN_ADDRESS =
                      address(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE);
                  event UpdateRegistryAddress(address indexed registryAddress);
                  constructor(address _registry) Ownable() {
                      registry = _registry;
                  }
                  modifier onlyRegistry() {
                      require(msg.sender == registry, MovrErrors.INVALID_SENDER);
                      _;
                  }
                  function updateRegistryAddress(address newRegistry) external onlyOwner {
                      registry = newRegistry;
                      emit UpdateRegistryAddress(newRegistry);
                  }
                  function rescueFunds(
                      address token,
                      address userAddress,
                      uint256 amount
                  ) external onlyOwner {
                      IERC20(token).safeTransfer(userAddress, amount);
                  }
                  function rescueEther(
                      address payable userAddress,
                      uint256 amount
                  ) external onlyOwner {
                      userAddress.transfer(amount);
                  }
                  function outboundTransferTo(
                      uint256 _amount,
                      address _from,
                      address _receiverAddress,
                      address _token,
                      uint256 _toChainId,
                      bytes memory _extraData
                  ) external payable virtual;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.8.0;
              library MovrErrors {
                  string internal constant ADDRESS_0_PROVIDED = "ADDRESS_0_PROVIDED";
                  string internal constant EMPTY_INPUT = "EMPTY_INPUT";
                  string internal constant LENGTH_MISMATCH = "LENGTH_MISMATCH";
                  string internal constant INVALID_VALUE = "INVALID_VALUE";
                  string internal constant INVALID_AMT = "INVALID_AMT";
                  string internal constant IMPL_NOT_FOUND = "IMPL_NOT_FOUND";
                  string internal constant ROUTE_NOT_FOUND = "ROUTE_NOT_FOUND";
                  string internal constant IMPL_NOT_ALLOWED = "IMPL_NOT_ALLOWED";
                  string internal constant ROUTE_NOT_ALLOWED = "ROUTE_NOT_ALLOWED";
                  string internal constant INVALID_CHAIN_DATA = "INVALID_CHAIN_DATA";
                  string internal constant CHAIN_NOT_SUPPORTED = "CHAIN_NOT_SUPPORTED";
                  string internal constant TOKEN_NOT_SUPPORTED = "TOKEN_NOT_SUPPORTED";
                  string internal constant NOT_IMPLEMENTED = "NOT_IMPLEMENTED";
                  string internal constant INVALID_SENDER = "INVALID_SENDER";
                  string internal constant INVALID_BRIDGE_ID = "INVALID_BRIDGE_ID";
                  string internal constant MIDDLEWARE_ACTION_FAILED =
                      "MIDDLEWARE_ACTION_FAILED";
                  string internal constant VALUE_SHOULD_BE_ZERO = "VALUE_SHOULD_BE_ZERO";
                  string internal constant VALUE_SHOULD_NOT_BE_ZERO = "VALUE_SHOULD_NOT_BE_ZERO";
                  string internal constant VALUE_NOT_ENOUGH = "VALUE_NOT_ENOUGH";
                  string internal constant VALUE_NOT_EQUAL_TO_AMOUNT = "VALUE_NOT_EQUAL_TO_AMOUNT";
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.4;
              /**
              @title L1Bridge Hop Interface
              @notice L1 Hop Bridge, Used to transfer from L1 to L2s. 
              */
              interface IHopL1Bridge {
                  function sendToL2(
                      uint256 chainId,
                      address recipient,
                      uint256 amount,
                      uint256 amountOutMin,
                      uint256 deadline,
                      address relayer,
                      uint256 relayerFee
                  ) external payable;
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
              pragma solidity ^0.8.1;
              /**
               * @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
                   * ====
                   *
                   * [IMPORTANT]
                   * ====
                   * You shouldn't rely on `isContract` to protect against flash loan attacks!
                   *
                   * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                   * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                   * constructor.
                   * ====
                   */
                  function isContract(address account) internal view returns (bool) {
                      // This method relies on extcodesize/address.code.length, which returns 0
                      // for contracts in construction, since the code is only stored at the end
                      // of the constructor execution.
                      return account.code.length > 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");
                      (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");
                      (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");
                      (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");
                      (bool success, bytes memory returndata) = target.delegatecall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                   * revert reason using the provided one.
                   *
                   * _Available since v4.3._
                   */
                  function verifyCallResult(
                      bool success,
                      bytes memory returndata,
                      string memory errorMessage
                  ) internal 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
                              assembly {
                                  let returndata_size := mload(returndata)
                                  revert(add(32, returndata), returndata_size)
                              }
                          } else {
                              revert(errorMessage);
                          }
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
              pragma solidity ^0.8.0;
              import "../utils/Context.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              abstract contract Ownable is Context {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  constructor() {
                      _transferOwnership(_msgSender());
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view virtual returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(owner() == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      _transferOwnership(address(0));
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      _transferOwnership(newOwner);
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Internal function without access restriction.
                   */
                  function _transferOwnership(address newOwner) internal virtual {
                      address oldOwner = _owner;
                      _owner = newOwner;
                      emit OwnershipTransferred(oldOwner, newOwner);
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes calldata) {
                      return msg.data;
                  }
              }
              

              File 3 of 8: CanonicalTransactionChain
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { AddressAliasHelper } from "../../standards/AddressAliasHelper.sol";
              import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
              import { Lib_AddressResolver } from "../../libraries/resolver/Lib_AddressResolver.sol";
              /* Interface Imports */
              import { ICanonicalTransactionChain } from "./ICanonicalTransactionChain.sol";
              import { IChainStorageContainer } from "./IChainStorageContainer.sol";
              /**
               * @title CanonicalTransactionChain
               * @dev The Canonical Transaction Chain (CTC) contract is an append-only log of transactions
               * which must be applied to the rollup state. It defines the ordering of rollup transactions by
               * writing them to the 'CTC:batches' instance of the Chain Storage Container.
               * The CTC also allows any account to 'enqueue' an L2 transaction, which will require that the
               * Sequencer will eventually append it to the rollup state.
               *
               * Runtime target: EVM
               */
              contract CanonicalTransactionChain is ICanonicalTransactionChain, Lib_AddressResolver {
                  /*************
                   * Constants *
                   *************/
                  // L2 tx gas-related
                  uint256 public constant MIN_ROLLUP_TX_GAS = 100000;
                  uint256 public constant MAX_ROLLUP_TX_SIZE = 50000;
                  // The approximate cost of calling the enqueue function
                  uint256 public enqueueGasCost;
                  // The ratio of the cost of L1 gas to the cost of L2 gas
                  uint256 public l2GasDiscountDivisor;
                  // The amount of L2 gas which can be forwarded to L2 without spam prevention via 'gas burn'.
                  // Calculated as the product of l2GasDiscountDivisor * enqueueGasCost.
                  // See comments in enqueue() for further detail.
                  uint256 public enqueueL2GasPrepaid;
                  // Encoding-related (all in bytes)
                  uint256 internal constant BATCH_CONTEXT_SIZE = 16;
                  uint256 internal constant BATCH_CONTEXT_LENGTH_POS = 12;
                  uint256 internal constant BATCH_CONTEXT_START_POS = 15;
                  uint256 internal constant TX_DATA_HEADER_SIZE = 3;
                  uint256 internal constant BYTES_TILL_TX_DATA = 65;
                  /*************
                   * Variables *
                   *************/
                  uint256 public maxTransactionGasLimit;
                  /***************
                   * Queue State *
                   ***************/
                  uint40 private _nextQueueIndex; // index of the first queue element not yet included
                  Lib_OVMCodec.QueueElement[] queueElements;
                  /***************
                   * Constructor *
                   ***************/
                  constructor(
                      address _libAddressManager,
                      uint256 _maxTransactionGasLimit,
                      uint256 _l2GasDiscountDivisor,
                      uint256 _enqueueGasCost
                  ) Lib_AddressResolver(_libAddressManager) {
                      maxTransactionGasLimit = _maxTransactionGasLimit;
                      l2GasDiscountDivisor = _l2GasDiscountDivisor;
                      enqueueGasCost = _enqueueGasCost;
                      enqueueL2GasPrepaid = _l2GasDiscountDivisor * _enqueueGasCost;
                  }
                  /**********************
                   * Function Modifiers *
                   **********************/
                  /**
                   * Modifier to enforce that, if configured, only the Burn Admin may
                   * successfully call a method.
                   */
                  modifier onlyBurnAdmin() {
                      require(msg.sender == libAddressManager.owner(), "Only callable by the Burn Admin.");
                      _;
                  }
                  /*******************************
                   * Authorized Setter Functions *
                   *******************************/
                  /**
                   * Allows the Burn Admin to update the parameters which determine the amount of gas to burn.
                   * The value of enqueueL2GasPrepaid is immediately updated as well.
                   */
                  function setGasParams(uint256 _l2GasDiscountDivisor, uint256 _enqueueGasCost)
                      external
                      onlyBurnAdmin
                  {
                      enqueueGasCost = _enqueueGasCost;
                      l2GasDiscountDivisor = _l2GasDiscountDivisor;
                      // See the comment in enqueue() for the rationale behind this formula.
                      enqueueL2GasPrepaid = _l2GasDiscountDivisor * _enqueueGasCost;
                      emit L2GasParamsUpdated(l2GasDiscountDivisor, enqueueGasCost, enqueueL2GasPrepaid);
                  }
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Accesses the batch storage container.
                   * @return Reference to the batch storage container.
                   */
                  function batches() public view returns (IChainStorageContainer) {
                      return IChainStorageContainer(resolve("ChainStorageContainer-CTC-batches"));
                  }
                  /**
                   * Retrieves the total number of elements submitted.
                   * @return _totalElements Total submitted elements.
                   */
                  function getTotalElements() public view returns (uint256 _totalElements) {
                      (uint40 totalElements, , , ) = _getBatchExtraData();
                      return uint256(totalElements);
                  }
                  /**
                   * Retrieves the total number of batches submitted.
                   * @return _totalBatches Total submitted batches.
                   */
                  function getTotalBatches() public view returns (uint256 _totalBatches) {
                      return batches().length();
                  }
                  /**
                   * Returns the index of the next element to be enqueued.
                   * @return Index for the next queue element.
                   */
                  function getNextQueueIndex() public view returns (uint40) {
                      return _nextQueueIndex;
                  }
                  /**
                   * Returns the timestamp of the last transaction.
                   * @return Timestamp for the last transaction.
                   */
                  function getLastTimestamp() public view returns (uint40) {
                      (, , uint40 lastTimestamp, ) = _getBatchExtraData();
                      return lastTimestamp;
                  }
                  /**
                   * Returns the blocknumber of the last transaction.
                   * @return Blocknumber for the last transaction.
                   */
                  function getLastBlockNumber() public view returns (uint40) {
                      (, , , uint40 lastBlockNumber) = _getBatchExtraData();
                      return lastBlockNumber;
                  }
                  /**
                   * Gets the queue element at a particular index.
                   * @param _index Index of the queue element to access.
                   * @return _element Queue element at the given index.
                   */
                  function getQueueElement(uint256 _index)
                      public
                      view
                      returns (Lib_OVMCodec.QueueElement memory _element)
                  {
                      return queueElements[_index];
                  }
                  /**
                   * Get the number of queue elements which have not yet been included.
                   * @return Number of pending queue elements.
                   */
                  function getNumPendingQueueElements() public view returns (uint40) {
                      return uint40(queueElements.length) - _nextQueueIndex;
                  }
                  /**
                   * Retrieves the length of the queue, including
                   * both pending and canonical transactions.
                   * @return Length of the queue.
                   */
                  function getQueueLength() public view returns (uint40) {
                      return uint40(queueElements.length);
                  }
                  /**
                   * Adds a transaction to the queue.
                   * @param _target Target L2 contract to send the transaction to.
                   * @param _gasLimit Gas limit for the enqueued L2 transaction.
                   * @param _data Transaction data.
                   */
                  function enqueue(
                      address _target,
                      uint256 _gasLimit,
                      bytes memory _data
                  ) external {
                      require(
                          _data.length <= MAX_ROLLUP_TX_SIZE,
                          "Transaction data size exceeds maximum for rollup transaction."
                      );
                      require(
                          _gasLimit <= maxTransactionGasLimit,
                          "Transaction gas limit exceeds maximum for rollup transaction."
                      );
                      require(_gasLimit >= MIN_ROLLUP_TX_GAS, "Transaction gas limit too low to enqueue.");
                      // Transactions submitted to the queue lack a method for paying gas fees to the Sequencer.
                      // So we need to prevent spam attacks by ensuring that the cost of enqueueing a transaction
                      // from L1 to L2 is not underpriced. For transaction with a high L2 gas limit, we do this by
                      // burning some extra gas on L1. Of course there is also some intrinsic cost to enqueueing a
                      // transaction, so we want to make sure not to over-charge (by burning too much L1 gas).
                      // Therefore, we define 'enqueueL2GasPrepaid' as the L2 gas limit above which we must burn
                      // additional gas on L1. This threshold is the product of two inputs:
                      // 1. enqueueGasCost: the base cost of calling this function.
                      // 2. l2GasDiscountDivisor: the ratio between the cost of gas on L1 and L2. This is a
                      //    positive integer, meaning we assume L2 gas is always less costly.
                      // The calculation below for gasToConsume can be seen as converting the difference (between
                      // the specified L2 gas limit and the prepaid L2 gas limit) to an L1 gas amount.
                      if (_gasLimit > enqueueL2GasPrepaid) {
                          uint256 gasToConsume = (_gasLimit - enqueueL2GasPrepaid) / l2GasDiscountDivisor;
                          uint256 startingGas = gasleft();
                          // Although this check is not necessary (burn below will run out of gas if not true), it
                          // gives the user an explicit reason as to why the enqueue attempt failed.
                          require(startingGas > gasToConsume, "Insufficient gas for L2 rate limiting burn.");
                          uint256 i;
                          while (startingGas - gasleft() < gasToConsume) {
                              i++;
                          }
                      }
                      // Apply an aliasing unless msg.sender == tx.origin. This prevents an attack in which a
                      // contract on L1 has the same address as a contract on L2 but doesn't have the same code.
                      // We can safely ignore this for EOAs because they're guaranteed to have the same "code"
                      // (i.e. no code at all). This also makes it possible for users to interact with contracts
                      // on L2 even when the Sequencer is down.
                      address sender;
                      if (msg.sender == tx.origin) {
                          sender = msg.sender;
                      } else {
                          sender = AddressAliasHelper.applyL1ToL2Alias(msg.sender);
                      }
                      bytes32 transactionHash = keccak256(abi.encode(sender, _target, _gasLimit, _data));
                      queueElements.push(
                          Lib_OVMCodec.QueueElement({
                              transactionHash: transactionHash,
                              timestamp: uint40(block.timestamp),
                              blockNumber: uint40(block.number)
                          })
                      );
                      uint256 queueIndex = queueElements.length - 1;
                      emit TransactionEnqueued(sender, _target, _gasLimit, _data, queueIndex, block.timestamp);
                  }
                  /**
                   * Allows the sequencer to append a batch of transactions.
                   * @dev This function uses a custom encoding scheme for efficiency reasons.
                   * .param _shouldStartAtElement Specific batch we expect to start appending to.
                   * .param _totalElementsToAppend Total number of batch elements we expect to append.
                   * .param _contexts Array of batch contexts.
                   * .param _transactionDataFields Array of raw transaction data.
                   */
                  function appendSequencerBatch() external {
                      uint40 shouldStartAtElement;
                      uint24 totalElementsToAppend;
                      uint24 numContexts;
                      assembly {
                          shouldStartAtElement := shr(216, calldataload(4))
                          totalElementsToAppend := shr(232, calldataload(9))
                          numContexts := shr(232, calldataload(12))
                      }
                      require(
                          shouldStartAtElement == getTotalElements(),
                          "Actual batch start index does not match expected start index."
                      );
                      require(
                          msg.sender == resolve("OVM_Sequencer"),
                          "Function can only be called by the Sequencer."
                      );
                      uint40 nextTransactionPtr = uint40(
                          BATCH_CONTEXT_START_POS + BATCH_CONTEXT_SIZE * numContexts
                      );
                      require(msg.data.length >= nextTransactionPtr, "Not enough BatchContexts provided.");
                      // Counter for number of sequencer transactions appended so far.
                      uint32 numSequencerTransactions = 0;
                      // Cache the _nextQueueIndex storage variable to a temporary stack variable.
                      // This is safe as long as nothing reads or writes to the storage variable
                      // until it is updated by the temp variable.
                      uint40 nextQueueIndex = _nextQueueIndex;
                      BatchContext memory curContext;
                      for (uint32 i = 0; i < numContexts; i++) {
                          BatchContext memory nextContext = _getBatchContext(i);
                          // Now we can update our current context.
                          curContext = nextContext;
                          // Process sequencer transactions first.
                          numSequencerTransactions += uint32(curContext.numSequencedTransactions);
                          // Now process any subsequent queue transactions.
                          nextQueueIndex += uint40(curContext.numSubsequentQueueTransactions);
                      }
                      require(
                          nextQueueIndex <= queueElements.length,
                          "Attempted to append more elements than are available in the queue."
                      );
                      // Generate the required metadata that we need to append this batch
                      uint40 numQueuedTransactions = totalElementsToAppend - numSequencerTransactions;
                      uint40 blockTimestamp;
                      uint40 blockNumber;
                      if (curContext.numSubsequentQueueTransactions == 0) {
                          // The last element is a sequencer tx, therefore pull timestamp and block number from
                          // the last context.
                          blockTimestamp = uint40(curContext.timestamp);
                          blockNumber = uint40(curContext.blockNumber);
                      } else {
                          // The last element is a queue tx, therefore pull timestamp and block number from the
                          // queue element.
                          // curContext.numSubsequentQueueTransactions > 0 which means that we've processed at
                          // least one queue element. We increment nextQueueIndex after processing each queue
                          // element, so the index of the last element we processed is nextQueueIndex - 1.
                          Lib_OVMCodec.QueueElement memory lastElement = queueElements[nextQueueIndex - 1];
                          blockTimestamp = lastElement.timestamp;
                          blockNumber = lastElement.blockNumber;
                      }
                      // Cache the previous blockhash to ensure all transaction data can be retrieved efficiently.
                      _appendBatch(
                          blockhash(block.number - 1),
                          totalElementsToAppend,
                          numQueuedTransactions,
                          blockTimestamp,
                          blockNumber
                      );
                      emit SequencerBatchAppended(
                          nextQueueIndex - numQueuedTransactions,
                          numQueuedTransactions,
                          getTotalElements()
                      );
                      // Update the _nextQueueIndex storage variable.
                      _nextQueueIndex = nextQueueIndex;
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Returns the BatchContext located at a particular index.
                   * @param _index The index of the BatchContext
                   * @return The BatchContext at the specified index.
                   */
                  function _getBatchContext(uint256 _index) internal pure returns (BatchContext memory) {
                      uint256 contextPtr = 15 + _index * BATCH_CONTEXT_SIZE;
                      uint256 numSequencedTransactions;
                      uint256 numSubsequentQueueTransactions;
                      uint256 ctxTimestamp;
                      uint256 ctxBlockNumber;
                      assembly {
                          numSequencedTransactions := shr(232, calldataload(contextPtr))
                          numSubsequentQueueTransactions := shr(232, calldataload(add(contextPtr, 3)))
                          ctxTimestamp := shr(216, calldataload(add(contextPtr, 6)))
                          ctxBlockNumber := shr(216, calldataload(add(contextPtr, 11)))
                      }
                      return
                          BatchContext({
                              numSequencedTransactions: numSequencedTransactions,
                              numSubsequentQueueTransactions: numSubsequentQueueTransactions,
                              timestamp: ctxTimestamp,
                              blockNumber: ctxBlockNumber
                          });
                  }
                  /**
                   * Parses the batch context from the extra data.
                   * @return Total number of elements submitted.
                   * @return Index of the next queue element.
                   */
                  function _getBatchExtraData()
                      internal
                      view
                      returns (
                          uint40,
                          uint40,
                          uint40,
                          uint40
                      )
                  {
                      bytes27 extraData = batches().getGlobalMetadata();
                      uint40 totalElements;
                      uint40 nextQueueIndex;
                      uint40 lastTimestamp;
                      uint40 lastBlockNumber;
                      // solhint-disable max-line-length
                      assembly {
                          extraData := shr(40, extraData)
                          totalElements := and(
                              extraData,
                              0x000000000000000000000000000000000000000000000000000000FFFFFFFFFF
                          )
                          nextQueueIndex := shr(
                              40,
                              and(extraData, 0x00000000000000000000000000000000000000000000FFFFFFFFFF0000000000)
                          )
                          lastTimestamp := shr(
                              80,
                              and(extraData, 0x0000000000000000000000000000000000FFFFFFFFFF00000000000000000000)
                          )
                          lastBlockNumber := shr(
                              120,
                              and(extraData, 0x000000000000000000000000FFFFFFFFFF000000000000000000000000000000)
                          )
                      }
                      // solhint-enable max-line-length
                      return (totalElements, nextQueueIndex, lastTimestamp, lastBlockNumber);
                  }
                  /**
                   * Encodes the batch context for the extra data.
                   * @param _totalElements Total number of elements submitted.
                   * @param _nextQueueIdx Index of the next queue element.
                   * @param _timestamp Timestamp for the last batch.
                   * @param _blockNumber Block number of the last batch.
                   * @return Encoded batch context.
                   */
                  function _makeBatchExtraData(
                      uint40 _totalElements,
                      uint40 _nextQueueIdx,
                      uint40 _timestamp,
                      uint40 _blockNumber
                  ) internal pure returns (bytes27) {
                      bytes27 extraData;
                      assembly {
                          extraData := _totalElements
                          extraData := or(extraData, shl(40, _nextQueueIdx))
                          extraData := or(extraData, shl(80, _timestamp))
                          extraData := or(extraData, shl(120, _blockNumber))
                          extraData := shl(40, extraData)
                      }
                      return extraData;
                  }
                  /**
                   * Inserts a batch into the chain of batches.
                   * @param _transactionRoot Root of the transaction tree for this batch.
                   * @param _batchSize Number of elements in the batch.
                   * @param _numQueuedTransactions Number of queue transactions in the batch.
                   * @param _timestamp The latest batch timestamp.
                   * @param _blockNumber The latest batch blockNumber.
                   */
                  function _appendBatch(
                      bytes32 _transactionRoot,
                      uint256 _batchSize,
                      uint256 _numQueuedTransactions,
                      uint40 _timestamp,
                      uint40 _blockNumber
                  ) internal {
                      IChainStorageContainer batchesRef = batches();
                      (uint40 totalElements, uint40 nextQueueIndex, , ) = _getBatchExtraData();
                      Lib_OVMCodec.ChainBatchHeader memory header = Lib_OVMCodec.ChainBatchHeader({
                          batchIndex: batchesRef.length(),
                          batchRoot: _transactionRoot,
                          batchSize: _batchSize,
                          prevTotalElements: totalElements,
                          extraData: hex""
                      });
                      emit TransactionBatchAppended(
                          header.batchIndex,
                          header.batchRoot,
                          header.batchSize,
                          header.prevTotalElements,
                          header.extraData
                      );
                      bytes32 batchHeaderHash = Lib_OVMCodec.hashBatchHeader(header);
                      bytes27 latestBatchContext = _makeBatchExtraData(
                          totalElements + uint40(header.batchSize),
                          nextQueueIndex + uint40(_numQueuedTransactions),
                          _timestamp,
                          _blockNumber
                      );
                      batchesRef.push(batchHeaderHash, latestBatchContext);
                  }
              }
              // SPDX-License-Identifier: Apache-2.0
              /*
               * Copyright 2019-2021, Offchain Labs, Inc.
               *
               * 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 ^0.8.7;
              library AddressAliasHelper {
                  uint160 constant offset = uint160(0x1111000000000000000000000000000000001111);
                  /// @notice Utility function that converts the address in the L1 that submitted a tx to
                  /// the inbox to the msg.sender viewed in the L2
                  /// @param l1Address the address in the L1 that triggered the tx to L2
                  /// @return l2Address L2 address as viewed in msg.sender
                  function applyL1ToL2Alias(address l1Address) internal pure returns (address l2Address) {
                      unchecked {
                          l2Address = address(uint160(l1Address) + offset);
                      }
                  }
                  /// @notice Utility function that converts the msg.sender viewed in the L2 to the
                  /// address in the L1 that submitted a tx to the inbox
                  /// @param l2Address L2 address as viewed in msg.sender
                  /// @return l1Address the address in the L1 that triggered the tx to L2
                  function undoL1ToL2Alias(address l2Address) internal pure returns (address l1Address) {
                      unchecked {
                          l1Address = address(uint160(l2Address) - offset);
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { Lib_RLPReader } from "../rlp/Lib_RLPReader.sol";
              import { Lib_RLPWriter } from "../rlp/Lib_RLPWriter.sol";
              import { Lib_BytesUtils } from "../utils/Lib_BytesUtils.sol";
              import { Lib_Bytes32Utils } from "../utils/Lib_Bytes32Utils.sol";
              /**
               * @title Lib_OVMCodec
               */
              library Lib_OVMCodec {
                  /*********
                   * Enums *
                   *********/
                  enum QueueOrigin {
                      SEQUENCER_QUEUE,
                      L1TOL2_QUEUE
                  }
                  /***********
                   * Structs *
                   ***********/
                  struct EVMAccount {
                      uint256 nonce;
                      uint256 balance;
                      bytes32 storageRoot;
                      bytes32 codeHash;
                  }
                  struct ChainBatchHeader {
                      uint256 batchIndex;
                      bytes32 batchRoot;
                      uint256 batchSize;
                      uint256 prevTotalElements;
                      bytes extraData;
                  }
                  struct ChainInclusionProof {
                      uint256 index;
                      bytes32[] siblings;
                  }
                  struct Transaction {
                      uint256 timestamp;
                      uint256 blockNumber;
                      QueueOrigin l1QueueOrigin;
                      address l1TxOrigin;
                      address entrypoint;
                      uint256 gasLimit;
                      bytes data;
                  }
                  struct TransactionChainElement {
                      bool isSequenced;
                      uint256 queueIndex; // QUEUED TX ONLY
                      uint256 timestamp; // SEQUENCER TX ONLY
                      uint256 blockNumber; // SEQUENCER TX ONLY
                      bytes txData; // SEQUENCER TX ONLY
                  }
                  struct QueueElement {
                      bytes32 transactionHash;
                      uint40 timestamp;
                      uint40 blockNumber;
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Encodes a standard OVM transaction.
                   * @param _transaction OVM transaction to encode.
                   * @return Encoded transaction bytes.
                   */
                  function encodeTransaction(Transaction memory _transaction)
                      internal
                      pure
                      returns (bytes memory)
                  {
                      return
                          abi.encodePacked(
                              _transaction.timestamp,
                              _transaction.blockNumber,
                              _transaction.l1QueueOrigin,
                              _transaction.l1TxOrigin,
                              _transaction.entrypoint,
                              _transaction.gasLimit,
                              _transaction.data
                          );
                  }
                  /**
                   * Hashes a standard OVM transaction.
                   * @param _transaction OVM transaction to encode.
                   * @return Hashed transaction
                   */
                  function hashTransaction(Transaction memory _transaction) internal pure returns (bytes32) {
                      return keccak256(encodeTransaction(_transaction));
                  }
                  /**
                   * @notice Decodes an RLP-encoded account state into a useful struct.
                   * @param _encoded RLP-encoded account state.
                   * @return Account state struct.
                   */
                  function decodeEVMAccount(bytes memory _encoded) internal pure returns (EVMAccount memory) {
                      Lib_RLPReader.RLPItem[] memory accountState = Lib_RLPReader.readList(_encoded);
                      return
                          EVMAccount({
                              nonce: Lib_RLPReader.readUint256(accountState[0]),
                              balance: Lib_RLPReader.readUint256(accountState[1]),
                              storageRoot: Lib_RLPReader.readBytes32(accountState[2]),
                              codeHash: Lib_RLPReader.readBytes32(accountState[3])
                          });
                  }
                  /**
                   * Calculates a hash for a given batch header.
                   * @param _batchHeader Header to hash.
                   * @return Hash of the header.
                   */
                  function hashBatchHeader(Lib_OVMCodec.ChainBatchHeader memory _batchHeader)
                      internal
                      pure
                      returns (bytes32)
                  {
                      return
                          keccak256(
                              abi.encode(
                                  _batchHeader.batchRoot,
                                  _batchHeader.batchSize,
                                  _batchHeader.prevTotalElements,
                                  _batchHeader.extraData
                              )
                          );
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { Lib_AddressManager } from "./Lib_AddressManager.sol";
              /**
               * @title Lib_AddressResolver
               */
              abstract contract Lib_AddressResolver {
                  /*************
                   * Variables *
                   *************/
                  Lib_AddressManager public libAddressManager;
                  /***************
                   * Constructor *
                   ***************/
                  /**
                   * @param _libAddressManager Address of the Lib_AddressManager.
                   */
                  constructor(address _libAddressManager) {
                      libAddressManager = Lib_AddressManager(_libAddressManager);
                  }
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Resolves the address associated with a given name.
                   * @param _name Name to resolve an address for.
                   * @return Address associated with the given name.
                   */
                  function resolve(string memory _name) public view returns (address) {
                      return libAddressManager.getAddress(_name);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.9.0;
              /* Library Imports */
              import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
              /* Interface Imports */
              import { IChainStorageContainer } from "./IChainStorageContainer.sol";
              /**
               * @title ICanonicalTransactionChain
               */
              interface ICanonicalTransactionChain {
                  /**********
                   * Events *
                   **********/
                  event L2GasParamsUpdated(
                      uint256 l2GasDiscountDivisor,
                      uint256 enqueueGasCost,
                      uint256 enqueueL2GasPrepaid
                  );
                  event TransactionEnqueued(
                      address indexed _l1TxOrigin,
                      address indexed _target,
                      uint256 _gasLimit,
                      bytes _data,
                      uint256 indexed _queueIndex,
                      uint256 _timestamp
                  );
                  event QueueBatchAppended(
                      uint256 _startingQueueIndex,
                      uint256 _numQueueElements,
                      uint256 _totalElements
                  );
                  event SequencerBatchAppended(
                      uint256 _startingQueueIndex,
                      uint256 _numQueueElements,
                      uint256 _totalElements
                  );
                  event TransactionBatchAppended(
                      uint256 indexed _batchIndex,
                      bytes32 _batchRoot,
                      uint256 _batchSize,
                      uint256 _prevTotalElements,
                      bytes _extraData
                  );
                  /***********
                   * Structs *
                   ***********/
                  struct BatchContext {
                      uint256 numSequencedTransactions;
                      uint256 numSubsequentQueueTransactions;
                      uint256 timestamp;
                      uint256 blockNumber;
                  }
                  /*******************************
                   * Authorized Setter Functions *
                   *******************************/
                  /**
                   * Allows the Burn Admin to update the parameters which determine the amount of gas to burn.
                   * The value of enqueueL2GasPrepaid is immediately updated as well.
                   */
                  function setGasParams(uint256 _l2GasDiscountDivisor, uint256 _enqueueGasCost) external;
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Accesses the batch storage container.
                   * @return Reference to the batch storage container.
                   */
                  function batches() external view returns (IChainStorageContainer);
                  /**
                   * Retrieves the total number of elements submitted.
                   * @return _totalElements Total submitted elements.
                   */
                  function getTotalElements() external view returns (uint256 _totalElements);
                  /**
                   * Retrieves the total number of batches submitted.
                   * @return _totalBatches Total submitted batches.
                   */
                  function getTotalBatches() external view returns (uint256 _totalBatches);
                  /**
                   * Returns the index of the next element to be enqueued.
                   * @return Index for the next queue element.
                   */
                  function getNextQueueIndex() external view returns (uint40);
                  /**
                   * Gets the queue element at a particular index.
                   * @param _index Index of the queue element to access.
                   * @return _element Queue element at the given index.
                   */
                  function getQueueElement(uint256 _index)
                      external
                      view
                      returns (Lib_OVMCodec.QueueElement memory _element);
                  /**
                   * Returns the timestamp of the last transaction.
                   * @return Timestamp for the last transaction.
                   */
                  function getLastTimestamp() external view returns (uint40);
                  /**
                   * Returns the blocknumber of the last transaction.
                   * @return Blocknumber for the last transaction.
                   */
                  function getLastBlockNumber() external view returns (uint40);
                  /**
                   * Get the number of queue elements which have not yet been included.
                   * @return Number of pending queue elements.
                   */
                  function getNumPendingQueueElements() external view returns (uint40);
                  /**
                   * Retrieves the length of the queue, including
                   * both pending and canonical transactions.
                   * @return Length of the queue.
                   */
                  function getQueueLength() external view returns (uint40);
                  /**
                   * Adds a transaction to the queue.
                   * @param _target Target contract to send the transaction to.
                   * @param _gasLimit Gas limit for the given transaction.
                   * @param _data Transaction data.
                   */
                  function enqueue(
                      address _target,
                      uint256 _gasLimit,
                      bytes memory _data
                  ) external;
                  /**
                   * Allows the sequencer to append a batch of transactions.
                   * @dev This function uses a custom encoding scheme for efficiency reasons.
                   * .param _shouldStartAtElement Specific batch we expect to start appending to.
                   * .param _totalElementsToAppend Total number of batch elements we expect to append.
                   * .param _contexts Array of batch contexts.
                   * .param _transactionDataFields Array of raw transaction data.
                   */
                  function appendSequencerBatch(
                      // uint40 _shouldStartAtElement,
                      // uint24 _totalElementsToAppend,
                      // BatchContext[] _contexts,
                      // bytes[] _transactionDataFields
                  ) external;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.9.0;
              /**
               * @title IChainStorageContainer
               */
              interface IChainStorageContainer {
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Sets the container's global metadata field. We're using `bytes27` here because we use five
                   * bytes to maintain the length of the underlying data structure, meaning we have an extra
                   * 27 bytes to store arbitrary data.
                   * @param _globalMetadata New global metadata to set.
                   */
                  function setGlobalMetadata(bytes27 _globalMetadata) external;
                  /**
                   * Retrieves the container's global metadata field.
                   * @return Container global metadata field.
                   */
                  function getGlobalMetadata() external view returns (bytes27);
                  /**
                   * Retrieves the number of objects stored in the container.
                   * @return Number of objects in the container.
                   */
                  function length() external view returns (uint256);
                  /**
                   * Pushes an object into the container.
                   * @param _object A 32 byte value to insert into the container.
                   */
                  function push(bytes32 _object) external;
                  /**
                   * Pushes an object into the container. Function allows setting the global metadata since
                   * we'll need to touch the "length" storage slot anyway, which also contains the global
                   * metadata (it's an optimization).
                   * @param _object A 32 byte value to insert into the container.
                   * @param _globalMetadata New global metadata for the container.
                   */
                  function push(bytes32 _object, bytes27 _globalMetadata) external;
                  /**
                   * Retrieves an object from the container.
                   * @param _index Index of the particular object to access.
                   * @return 32 byte object value.
                   */
                  function get(uint256 _index) external view returns (bytes32);
                  /**
                   * Removes all objects after and including a given index.
                   * @param _index Object index to delete from.
                   */
                  function deleteElementsAfterInclusive(uint256 _index) external;
                  /**
                   * Removes all objects after and including a given index. Also allows setting the global
                   * metadata field.
                   * @param _index Object index to delete from.
                   * @param _globalMetadata New global metadata for the container.
                   */
                  function deleteElementsAfterInclusive(uint256 _index, bytes27 _globalMetadata) external;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_RLPReader
               * @dev Adapted from "RLPReader" by Hamdi Allam ([email protected]).
               */
              library Lib_RLPReader {
                  /*************
                   * Constants *
                   *************/
                  uint256 internal constant MAX_LIST_LENGTH = 32;
                  /*********
                   * Enums *
                   *********/
                  enum RLPItemType {
                      DATA_ITEM,
                      LIST_ITEM
                  }
                  /***********
                   * Structs *
                   ***********/
                  struct RLPItem {
                      uint256 length;
                      uint256 ptr;
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Converts bytes to a reference to memory position and length.
                   * @param _in Input bytes to convert.
                   * @return Output memory reference.
                   */
                  function toRLPItem(bytes memory _in) internal pure returns (RLPItem memory) {
                      uint256 ptr;
                      assembly {
                          ptr := add(_in, 32)
                      }
                      return RLPItem({ length: _in.length, ptr: ptr });
                  }
                  /**
                   * Reads an RLP list value into a list of RLP items.
                   * @param _in RLP list value.
                   * @return Decoded RLP list items.
                   */
                  function readList(RLPItem memory _in) internal pure returns (RLPItem[] memory) {
                      (uint256 listOffset, , RLPItemType itemType) = _decodeLength(_in);
                      require(itemType == RLPItemType.LIST_ITEM, "Invalid RLP list value.");
                      // Solidity in-memory arrays can't be increased in size, but *can* be decreased in size by
                      // writing to the length. Since we can't know the number of RLP items without looping over
                      // the entire input, we'd have to loop twice to accurately size this array. It's easier to
                      // simply set a reasonable maximum list length and decrease the size before we finish.
                      RLPItem[] memory out = new RLPItem[](MAX_LIST_LENGTH);
                      uint256 itemCount = 0;
                      uint256 offset = listOffset;
                      while (offset < _in.length) {
                          require(itemCount < MAX_LIST_LENGTH, "Provided RLP list exceeds max list length.");
                          (uint256 itemOffset, uint256 itemLength, ) = _decodeLength(
                              RLPItem({ length: _in.length - offset, ptr: _in.ptr + offset })
                          );
                          out[itemCount] = RLPItem({ length: itemLength + itemOffset, ptr: _in.ptr + offset });
                          itemCount += 1;
                          offset += itemOffset + itemLength;
                      }
                      // Decrease the array size to match the actual item count.
                      assembly {
                          mstore(out, itemCount)
                      }
                      return out;
                  }
                  /**
                   * Reads an RLP list value into a list of RLP items.
                   * @param _in RLP list value.
                   * @return Decoded RLP list items.
                   */
                  function readList(bytes memory _in) internal pure returns (RLPItem[] memory) {
                      return readList(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP bytes value into bytes.
                   * @param _in RLP bytes value.
                   * @return Decoded bytes.
                   */
                  function readBytes(RLPItem memory _in) internal pure returns (bytes memory) {
                      (uint256 itemOffset, uint256 itemLength, RLPItemType itemType) = _decodeLength(_in);
                      require(itemType == RLPItemType.DATA_ITEM, "Invalid RLP bytes value.");
                      return _copy(_in.ptr, itemOffset, itemLength);
                  }
                  /**
                   * Reads an RLP bytes value into bytes.
                   * @param _in RLP bytes value.
                   * @return Decoded bytes.
                   */
                  function readBytes(bytes memory _in) internal pure returns (bytes memory) {
                      return readBytes(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP string value into a string.
                   * @param _in RLP string value.
                   * @return Decoded string.
                   */
                  function readString(RLPItem memory _in) internal pure returns (string memory) {
                      return string(readBytes(_in));
                  }
                  /**
                   * Reads an RLP string value into a string.
                   * @param _in RLP string value.
                   * @return Decoded string.
                   */
                  function readString(bytes memory _in) internal pure returns (string memory) {
                      return readString(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP bytes32 value into a bytes32.
                   * @param _in RLP bytes32 value.
                   * @return Decoded bytes32.
                   */
                  function readBytes32(RLPItem memory _in) internal pure returns (bytes32) {
                      require(_in.length <= 33, "Invalid RLP bytes32 value.");
                      (uint256 itemOffset, uint256 itemLength, RLPItemType itemType) = _decodeLength(_in);
                      require(itemType == RLPItemType.DATA_ITEM, "Invalid RLP bytes32 value.");
                      uint256 ptr = _in.ptr + itemOffset;
                      bytes32 out;
                      assembly {
                          out := mload(ptr)
                          // Shift the bytes over to match the item size.
                          if lt(itemLength, 32) {
                              out := div(out, exp(256, sub(32, itemLength)))
                          }
                      }
                      return out;
                  }
                  /**
                   * Reads an RLP bytes32 value into a bytes32.
                   * @param _in RLP bytes32 value.
                   * @return Decoded bytes32.
                   */
                  function readBytes32(bytes memory _in) internal pure returns (bytes32) {
                      return readBytes32(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP uint256 value into a uint256.
                   * @param _in RLP uint256 value.
                   * @return Decoded uint256.
                   */
                  function readUint256(RLPItem memory _in) internal pure returns (uint256) {
                      return uint256(readBytes32(_in));
                  }
                  /**
                   * Reads an RLP uint256 value into a uint256.
                   * @param _in RLP uint256 value.
                   * @return Decoded uint256.
                   */
                  function readUint256(bytes memory _in) internal pure returns (uint256) {
                      return readUint256(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP bool value into a bool.
                   * @param _in RLP bool value.
                   * @return Decoded bool.
                   */
                  function readBool(RLPItem memory _in) internal pure returns (bool) {
                      require(_in.length == 1, "Invalid RLP boolean value.");
                      uint256 ptr = _in.ptr;
                      uint256 out;
                      assembly {
                          out := byte(0, mload(ptr))
                      }
                      require(out == 0 || out == 1, "Lib_RLPReader: Invalid RLP boolean value, must be 0 or 1");
                      return out != 0;
                  }
                  /**
                   * Reads an RLP bool value into a bool.
                   * @param _in RLP bool value.
                   * @return Decoded bool.
                   */
                  function readBool(bytes memory _in) internal pure returns (bool) {
                      return readBool(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP address value into a address.
                   * @param _in RLP address value.
                   * @return Decoded address.
                   */
                  function readAddress(RLPItem memory _in) internal pure returns (address) {
                      if (_in.length == 1) {
                          return address(0);
                      }
                      require(_in.length == 21, "Invalid RLP address value.");
                      return address(uint160(readUint256(_in)));
                  }
                  /**
                   * Reads an RLP address value into a address.
                   * @param _in RLP address value.
                   * @return Decoded address.
                   */
                  function readAddress(bytes memory _in) internal pure returns (address) {
                      return readAddress(toRLPItem(_in));
                  }
                  /**
                   * Reads the raw bytes of an RLP item.
                   * @param _in RLP item to read.
                   * @return Raw RLP bytes.
                   */
                  function readRawBytes(RLPItem memory _in) internal pure returns (bytes memory) {
                      return _copy(_in);
                  }
                  /*********************
                   * Private Functions *
                   *********************/
                  /**
                   * Decodes the length of an RLP item.
                   * @param _in RLP item to decode.
                   * @return Offset of the encoded data.
                   * @return Length of the encoded data.
                   * @return RLP item type (LIST_ITEM or DATA_ITEM).
                   */
                  function _decodeLength(RLPItem memory _in)
                      private
                      pure
                      returns (
                          uint256,
                          uint256,
                          RLPItemType
                      )
                  {
                      require(_in.length > 0, "RLP item cannot be null.");
                      uint256 ptr = _in.ptr;
                      uint256 prefix;
                      assembly {
                          prefix := byte(0, mload(ptr))
                      }
                      if (prefix <= 0x7f) {
                          // Single byte.
                          return (0, 1, RLPItemType.DATA_ITEM);
                      } else if (prefix <= 0xb7) {
                          // Short string.
                          uint256 strLen = prefix - 0x80;
                          require(_in.length > strLen, "Invalid RLP short string.");
                          return (1, strLen, RLPItemType.DATA_ITEM);
                      } else if (prefix <= 0xbf) {
                          // Long string.
                          uint256 lenOfStrLen = prefix - 0xb7;
                          require(_in.length > lenOfStrLen, "Invalid RLP long string length.");
                          uint256 strLen;
                          assembly {
                              // Pick out the string length.
                              strLen := div(mload(add(ptr, 1)), exp(256, sub(32, lenOfStrLen)))
                          }
                          require(_in.length > lenOfStrLen + strLen, "Invalid RLP long string.");
                          return (1 + lenOfStrLen, strLen, RLPItemType.DATA_ITEM);
                      } else if (prefix <= 0xf7) {
                          // Short list.
                          uint256 listLen = prefix - 0xc0;
                          require(_in.length > listLen, "Invalid RLP short list.");
                          return (1, listLen, RLPItemType.LIST_ITEM);
                      } else {
                          // Long list.
                          uint256 lenOfListLen = prefix - 0xf7;
                          require(_in.length > lenOfListLen, "Invalid RLP long list length.");
                          uint256 listLen;
                          assembly {
                              // Pick out the list length.
                              listLen := div(mload(add(ptr, 1)), exp(256, sub(32, lenOfListLen)))
                          }
                          require(_in.length > lenOfListLen + listLen, "Invalid RLP long list.");
                          return (1 + lenOfListLen, listLen, RLPItemType.LIST_ITEM);
                      }
                  }
                  /**
                   * Copies the bytes from a memory location.
                   * @param _src Pointer to the location to read from.
                   * @param _offset Offset to start reading from.
                   * @param _length Number of bytes to read.
                   * @return Copied bytes.
                   */
                  function _copy(
                      uint256 _src,
                      uint256 _offset,
                      uint256 _length
                  ) private pure returns (bytes memory) {
                      bytes memory out = new bytes(_length);
                      if (out.length == 0) {
                          return out;
                      }
                      uint256 src = _src + _offset;
                      uint256 dest;
                      assembly {
                          dest := add(out, 32)
                      }
                      // Copy over as many complete words as we can.
                      for (uint256 i = 0; i < _length / 32; i++) {
                          assembly {
                              mstore(dest, mload(src))
                          }
                          src += 32;
                          dest += 32;
                      }
                      // Pick out the remaining bytes.
                      uint256 mask;
                      unchecked {
                          mask = 256**(32 - (_length % 32)) - 1;
                      }
                      assembly {
                          mstore(dest, or(and(mload(src), not(mask)), and(mload(dest), mask)))
                      }
                      return out;
                  }
                  /**
                   * Copies an RLP item into bytes.
                   * @param _in RLP item to copy.
                   * @return Copied bytes.
                   */
                  function _copy(RLPItem memory _in) private pure returns (bytes memory) {
                      return _copy(_in.ptr, 0, _in.length);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_RLPWriter
               * @author Bakaoh (with modifications)
               */
              library Lib_RLPWriter {
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * RLP encodes a byte string.
                   * @param _in The byte string to encode.
                   * @return The RLP encoded string in bytes.
                   */
                  function writeBytes(bytes memory _in) internal pure returns (bytes memory) {
                      bytes memory encoded;
                      if (_in.length == 1 && uint8(_in[0]) < 128) {
                          encoded = _in;
                      } else {
                          encoded = abi.encodePacked(_writeLength(_in.length, 128), _in);
                      }
                      return encoded;
                  }
                  /**
                   * RLP encodes a list of RLP encoded byte byte strings.
                   * @param _in The list of RLP encoded byte strings.
                   * @return The RLP encoded list of items in bytes.
                   */
                  function writeList(bytes[] memory _in) internal pure returns (bytes memory) {
                      bytes memory list = _flatten(_in);
                      return abi.encodePacked(_writeLength(list.length, 192), list);
                  }
                  /**
                   * RLP encodes a string.
                   * @param _in The string to encode.
                   * @return The RLP encoded string in bytes.
                   */
                  function writeString(string memory _in) internal pure returns (bytes memory) {
                      return writeBytes(bytes(_in));
                  }
                  /**
                   * RLP encodes an address.
                   * @param _in The address to encode.
                   * @return The RLP encoded address in bytes.
                   */
                  function writeAddress(address _in) internal pure returns (bytes memory) {
                      return writeBytes(abi.encodePacked(_in));
                  }
                  /**
                   * RLP encodes a uint.
                   * @param _in The uint256 to encode.
                   * @return The RLP encoded uint256 in bytes.
                   */
                  function writeUint(uint256 _in) internal pure returns (bytes memory) {
                      return writeBytes(_toBinary(_in));
                  }
                  /**
                   * RLP encodes a bool.
                   * @param _in The bool to encode.
                   * @return The RLP encoded bool in bytes.
                   */
                  function writeBool(bool _in) internal pure returns (bytes memory) {
                      bytes memory encoded = new bytes(1);
                      encoded[0] = (_in ? bytes1(0x01) : bytes1(0x80));
                      return encoded;
                  }
                  /*********************
                   * Private Functions *
                   *********************/
                  /**
                   * Encode the first byte, followed by the `len` in binary form if `length` is more than 55.
                   * @param _len The length of the string or the payload.
                   * @param _offset 128 if item is string, 192 if item is list.
                   * @return RLP encoded bytes.
                   */
                  function _writeLength(uint256 _len, uint256 _offset) private pure returns (bytes memory) {
                      bytes memory encoded;
                      if (_len < 56) {
                          encoded = new bytes(1);
                          encoded[0] = bytes1(uint8(_len) + uint8(_offset));
                      } else {
                          uint256 lenLen;
                          uint256 i = 1;
                          while (_len / i != 0) {
                              lenLen++;
                              i *= 256;
                          }
                          encoded = new bytes(lenLen + 1);
                          encoded[0] = bytes1(uint8(lenLen) + uint8(_offset) + 55);
                          for (i = 1; i <= lenLen; i++) {
                              encoded[i] = bytes1(uint8((_len / (256**(lenLen - i))) % 256));
                          }
                      }
                      return encoded;
                  }
                  /**
                   * Encode integer in big endian binary form with no leading zeroes.
                   * @notice TODO: This should be optimized with assembly to save gas costs.
                   * @param _x The integer to encode.
                   * @return RLP encoded bytes.
                   */
                  function _toBinary(uint256 _x) private pure returns (bytes memory) {
                      bytes memory b = abi.encodePacked(_x);
                      uint256 i = 0;
                      for (; i < 32; i++) {
                          if (b[i] != 0) {
                              break;
                          }
                      }
                      bytes memory res = new bytes(32 - i);
                      for (uint256 j = 0; j < res.length; j++) {
                          res[j] = b[i++];
                      }
                      return res;
                  }
                  /**
                   * Copies a piece of memory to another location.
                   * @notice From: https://github.com/Arachnid/solidity-stringutils/blob/master/src/strings.sol.
                   * @param _dest Destination location.
                   * @param _src Source location.
                   * @param _len Length of memory to copy.
                   */
                  function _memcpy(
                      uint256 _dest,
                      uint256 _src,
                      uint256 _len
                  ) private pure {
                      uint256 dest = _dest;
                      uint256 src = _src;
                      uint256 len = _len;
                      for (; len >= 32; len -= 32) {
                          assembly {
                              mstore(dest, mload(src))
                          }
                          dest += 32;
                          src += 32;
                      }
                      uint256 mask;
                      unchecked {
                          mask = 256**(32 - len) - 1;
                      }
                      assembly {
                          let srcpart := and(mload(src), not(mask))
                          let destpart := and(mload(dest), mask)
                          mstore(dest, or(destpart, srcpart))
                      }
                  }
                  /**
                   * Flattens a list of byte strings into one byte string.
                   * @notice From: https://github.com/sammayo/solidity-rlp-encoder/blob/master/RLPEncode.sol.
                   * @param _list List of byte strings to flatten.
                   * @return The flattened byte string.
                   */
                  function _flatten(bytes[] memory _list) private pure returns (bytes memory) {
                      if (_list.length == 0) {
                          return new bytes(0);
                      }
                      uint256 len;
                      uint256 i = 0;
                      for (; i < _list.length; i++) {
                          len += _list[i].length;
                      }
                      bytes memory flattened = new bytes(len);
                      uint256 flattenedPtr;
                      assembly {
                          flattenedPtr := add(flattened, 0x20)
                      }
                      for (i = 0; i < _list.length; i++) {
                          bytes memory item = _list[i];
                          uint256 listPtr;
                          assembly {
                              listPtr := add(item, 0x20)
                          }
                          _memcpy(flattenedPtr, listPtr, item.length);
                          flattenedPtr += _list[i].length;
                      }
                      return flattened;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_BytesUtils
               */
              library Lib_BytesUtils {
                  /**********************
                   * Internal Functions *
                   **********************/
                  function slice(
                      bytes memory _bytes,
                      uint256 _start,
                      uint256 _length
                  ) internal pure returns (bytes memory) {
                      require(_length + 31 >= _length, "slice_overflow");
                      require(_start + _length >= _start, "slice_overflow");
                      require(_bytes.length >= _start + _length, "slice_outOfBounds");
                      bytes memory tempBytes;
                      assembly {
                          switch iszero(_length)
                          case 0 {
                              // Get a location of some free memory and store it in tempBytes as
                              // Solidity does for memory variables.
                              tempBytes := mload(0x40)
                              // The first word of the slice result is potentially a partial
                              // word read from the original array. To read it, we calculate
                              // the length of that partial word and start copying that many
                              // bytes into the array. The first word we copy will start with
                              // data we don't care about, but the last `lengthmod` bytes will
                              // land at the beginning of the contents of the new array. When
                              // we're done copying, we overwrite the full first word with
                              // the actual length of the slice.
                              let lengthmod := and(_length, 31)
                              // The multiplication in the next line is necessary
                              // because when slicing multiples of 32 bytes (lengthmod == 0)
                              // the following copy loop was copying the origin's length
                              // and then ending prematurely not copying everything it should.
                              let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                              let end := add(mc, _length)
                              for {
                                  // The multiplication in the next line has the same exact purpose
                                  // as the one above.
                                  let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                              } lt(mc, end) {
                                  mc := add(mc, 0x20)
                                  cc := add(cc, 0x20)
                              } {
                                  mstore(mc, mload(cc))
                              }
                              mstore(tempBytes, _length)
                              //update free-memory pointer
                              //allocating the array padded to 32 bytes like the compiler does now
                              mstore(0x40, and(add(mc, 31), not(31)))
                          }
                          //if we want a zero-length slice let's just return a zero-length array
                          default {
                              tempBytes := mload(0x40)
                              //zero out the 32 bytes slice we are about to return
                              //we need to do it because Solidity does not garbage collect
                              mstore(tempBytes, 0)
                              mstore(0x40, add(tempBytes, 0x20))
                          }
                      }
                      return tempBytes;
                  }
                  function slice(bytes memory _bytes, uint256 _start) internal pure returns (bytes memory) {
                      if (_start >= _bytes.length) {
                          return bytes("");
                      }
                      return slice(_bytes, _start, _bytes.length - _start);
                  }
                  function toBytes32(bytes memory _bytes) internal pure returns (bytes32) {
                      if (_bytes.length < 32) {
                          bytes32 ret;
                          assembly {
                              ret := mload(add(_bytes, 32))
                          }
                          return ret;
                      }
                      return abi.decode(_bytes, (bytes32)); // will truncate if input length > 32 bytes
                  }
                  function toUint256(bytes memory _bytes) internal pure returns (uint256) {
                      return uint256(toBytes32(_bytes));
                  }
                  function toNibbles(bytes memory _bytes) internal pure returns (bytes memory) {
                      bytes memory nibbles = new bytes(_bytes.length * 2);
                      for (uint256 i = 0; i < _bytes.length; i++) {
                          nibbles[i * 2] = _bytes[i] >> 4;
                          nibbles[i * 2 + 1] = bytes1(uint8(_bytes[i]) % 16);
                      }
                      return nibbles;
                  }
                  function fromNibbles(bytes memory _bytes) internal pure returns (bytes memory) {
                      bytes memory ret = new bytes(_bytes.length / 2);
                      for (uint256 i = 0; i < ret.length; i++) {
                          ret[i] = (_bytes[i * 2] << 4) | (_bytes[i * 2 + 1]);
                      }
                      return ret;
                  }
                  function equal(bytes memory _bytes, bytes memory _other) internal pure returns (bool) {
                      return keccak256(_bytes) == keccak256(_other);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_Byte32Utils
               */
              library Lib_Bytes32Utils {
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Converts a bytes32 value to a boolean. Anything non-zero will be converted to "true."
                   * @param _in Input bytes32 value.
                   * @return Bytes32 as a boolean.
                   */
                  function toBool(bytes32 _in) internal pure returns (bool) {
                      return _in != 0;
                  }
                  /**
                   * Converts a boolean to a bytes32 value.
                   * @param _in Input boolean value.
                   * @return Boolean as a bytes32.
                   */
                  function fromBool(bool _in) internal pure returns (bytes32) {
                      return bytes32(uint256(_in ? 1 : 0));
                  }
                  /**
                   * Converts a bytes32 value to an address. Takes the *last* 20 bytes.
                   * @param _in Input bytes32 value.
                   * @return Bytes32 as an address.
                   */
                  function toAddress(bytes32 _in) internal pure returns (address) {
                      return address(uint160(uint256(_in)));
                  }
                  /**
                   * Converts an address to a bytes32.
                   * @param _in Input address value.
                   * @return Address as a bytes32.
                   */
                  function fromAddress(address _in) internal pure returns (bytes32) {
                      return bytes32(uint256(uint160(_in)));
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* External Imports */
              import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
              /**
               * @title Lib_AddressManager
               */
              contract Lib_AddressManager is Ownable {
                  /**********
                   * Events *
                   **********/
                  event AddressSet(string indexed _name, address _newAddress, address _oldAddress);
                  /*************
                   * Variables *
                   *************/
                  mapping(bytes32 => address) private addresses;
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Changes the address associated with a particular name.
                   * @param _name String name to associate an address with.
                   * @param _address Address to associate with the name.
                   */
                  function setAddress(string memory _name, address _address) external onlyOwner {
                      bytes32 nameHash = _getNameHash(_name);
                      address oldAddress = addresses[nameHash];
                      addresses[nameHash] = _address;
                      emit AddressSet(_name, _address, oldAddress);
                  }
                  /**
                   * Retrieves the address associated with a given name.
                   * @param _name Name to retrieve an address for.
                   * @return Address associated with the given name.
                   */
                  function getAddress(string memory _name) external view returns (address) {
                      return addresses[_getNameHash(_name)];
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Computes the hash of a name.
                   * @param _name Name to compute a hash for.
                   * @return Hash of the given name.
                   */
                  function _getNameHash(string memory _name) internal pure returns (bytes32) {
                      return keccak256(abi.encodePacked(_name));
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "../utils/Context.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              abstract contract Ownable is Context {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  constructor() {
                      _setOwner(_msgSender());
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view virtual returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(owner() == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      _setOwner(address(0));
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      _setOwner(newOwner);
                  }
                  function _setOwner(address newOwner) private {
                      address oldOwner = _owner;
                      _owner = newOwner;
                      emit OwnershipTransferred(oldOwner, newOwner);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              /**
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes calldata) {
                      return msg.data;
                  }
              }
              

              File 4 of 8: Lib_ResolvedDelegateProxy
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              import "../utils/Context.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              abstract contract Ownable is Context {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  constructor () internal {
                      address msgSender = _msgSender();
                      _owner = msgSender;
                      emit OwnershipTransferred(address(0), msgSender);
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view virtual returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(owner() == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      emit OwnershipTransferred(_owner, address(0));
                      _owner = address(0);
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      emit OwnershipTransferred(_owner, newOwner);
                      _owner = newOwner;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              /*
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with GSN meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address payable) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes memory) {
                      this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                      return msg.data;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.8.0;
              /* External Imports */
              import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
              /**
               * @title Lib_AddressManager
               */
              contract Lib_AddressManager is Ownable {
                  /**********
                   * Events *
                   **********/
                  event AddressSet(
                      string indexed _name,
                      address _newAddress,
                      address _oldAddress
                  );
                  /*************
                   * Variables *
                   *************/
                  mapping (bytes32 => address) private addresses;
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Changes the address associated with a particular name.
                   * @param _name String name to associate an address with.
                   * @param _address Address to associate with the name.
                   */
                  function setAddress(
                      string memory _name,
                      address _address
                  )
                      external
                      onlyOwner
                  {
                      bytes32 nameHash = _getNameHash(_name);
                      address oldAddress = addresses[nameHash];
                      addresses[nameHash] = _address;
                      emit AddressSet(
                          _name,
                          _address,
                          oldAddress
                      );
                  }
                  /**
                   * Retrieves the address associated with a given name.
                   * @param _name Name to retrieve an address for.
                   * @return Address associated with the given name.
                   */
                  function getAddress(
                      string memory _name
                  )
                      external
                      view
                      returns (
                          address
                      )
                  {
                      return addresses[_getNameHash(_name)];
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Computes the hash of a name.
                   * @param _name Name to compute a hash for.
                   * @return Hash of the given name.
                   */
                  function _getNameHash(
                      string memory _name
                  )
                      internal
                      pure
                      returns (
                          bytes32
                      )
                  {
                      return keccak256(abi.encodePacked(_name));
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.8.0;
              /* Library Imports */
              import { Lib_AddressManager } from "./Lib_AddressManager.sol";
              /**
               * @title Lib_ResolvedDelegateProxy
               */
              contract Lib_ResolvedDelegateProxy {
                  /*************
                   * Variables *
                   *************/
                  // Using mappings to store fields to avoid overwriting storage slots in the
                  // implementation contract. For example, instead of storing these fields at
                  // storage slot `0` & `1`, they are stored at `keccak256(key + slot)`.
                  // See: https://solidity.readthedocs.io/en/v0.7.0/internals/layout_in_storage.html
                  // NOTE: Do not use this code in your own contract system.
                  //      There is a known flaw in this contract, and we will remove it from the repository
                  //      in the near future. Due to the very limited way that we are using it, this flaw is
                  //      not an issue in our system.
                  mapping (address => string) private implementationName;
                  mapping (address => Lib_AddressManager) private addressManager;
                  /***************
                   * Constructor *
                   ***************/
                  /**
                   * @param _libAddressManager Address of the Lib_AddressManager.
                   * @param _implementationName implementationName of the contract to proxy to.
                   */
                  constructor(
                      address _libAddressManager,
                      string memory _implementationName
                  ) {
                      addressManager[address(this)] = Lib_AddressManager(_libAddressManager);
                      implementationName[address(this)] = _implementationName;
                  }
                  /*********************
                   * Fallback Function *
                   *********************/
                  fallback()
                      external
                      payable
                  {
                      address target = addressManager[address(this)].getAddress(
                          (implementationName[address(this)])
                      );
                      require(
                          target != address(0),
                          "Target address must be initialized."
                      );
                      (bool success, bytes memory returndata) = target.delegatecall(msg.data);
                      if (success == true) {
                          assembly {
                              return(add(returndata, 0x20), mload(returndata))
                          }
                      } else {
                          assembly {
                              revert(add(returndata, 0x20), mload(returndata))
                          }
                      }
                  }
              }
              

              File 5 of 8: L1_ETH_Bridge
              // SPDX-License-Identifier: MIT
              pragma solidity 0.6.12;
              pragma experimental ABIEncoderV2;
              import "./L1_Bridge.sol";
              /**
               * @dev A L1_Bridge that uses an ETH as the canonical token
               */
              contract L1_ETH_Bridge is L1_Bridge {
                  constructor (address[] memory bonders, address _governance) public L1_Bridge(bonders, _governance) {}
                  /* ========== Override Functions ========== */
                  function _transferFromBridge(address recipient, uint256 amount) internal override {
                      (bool success, ) = recipient.call{value: amount}(new bytes(0));
                      require(success, 'L1_ETH_BRG: ETH transfer failed');
                  }
                  function _transferToBridge(address /*from*/, uint256 amount) internal override {
                      require(msg.value == amount, "L1_ETH_BRG: Value does not match amount");
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity 0.6.12;
              pragma experimental ABIEncoderV2;
              import "./Bridge.sol";
              import "../interfaces/IMessengerWrapper.sol";
              /**
               * @dev L1_Bridge is responsible for the bonding and challenging of TransferRoots. All TransferRoots
               * originate in the L1_Bridge through `bondTransferRoot` and are propagated up to destination L2s.
               */
              abstract contract L1_Bridge is Bridge {
                  struct TransferBond {
                      address bonder;
                      uint256 createdAt;
                      uint256 totalAmount;
                      uint256 challengeStartTime;
                      address challenger;
                      bool challengeResolved;
                  }
                  /* ========== State ========== */
                  mapping(uint256 => mapping(bytes32 => uint256)) public transferRootCommittedAt;
                  mapping(bytes32 => TransferBond) public transferBonds;
                  mapping(uint256 => mapping(address => uint256)) public timeSlotToAmountBonded;
                  mapping(uint256 => uint256) public chainBalance;
                  /* ========== Config State ========== */
                  address public governance;
                  mapping(uint256 => IMessengerWrapper) public crossDomainMessengerWrappers;
                  mapping(uint256 => bool) public isChainIdPaused;
                  uint256 public challengePeriod = 1 days;
                  uint256 public challengeResolutionPeriod = 10 days;
                  uint256 public minTransferRootBondDelay = 15 minutes;
                  
                  uint256 public constant CHALLENGE_AMOUNT_DIVISOR = 10;
                  uint256 public constant TIME_SLOT_SIZE = 4 hours;
                  /* ========== Events ========== */
                  event TransferSentToL2(
                      uint256 indexed chainId,
                      address indexed recipient,
                      uint256 amount,
                      uint256 amountOutMin,
                      uint256 deadline,
                      address indexed relayer,
                      uint256 relayerFee
                  );
                  event TransferRootBonded (
                      bytes32 indexed root,
                      uint256 amount
                  );
                  event TransferRootConfirmed(
                      uint256 indexed originChainId,
                      uint256 indexed destinationChainId,
                      bytes32 indexed rootHash,
                      uint256 totalAmount
                  );
                  event TransferBondChallenged(
                      bytes32 indexed transferRootId,
                      bytes32 indexed rootHash,
                      uint256 originalAmount
                  );
                  event ChallengeResolved(
                      bytes32 indexed transferRootId,
                      bytes32 indexed rootHash,
                      uint256 originalAmount
                  );
                  /* ========== Modifiers ========== */
                  modifier onlyL2Bridge(uint256 chainId) {
                      IMessengerWrapper messengerWrapper = crossDomainMessengerWrappers[chainId];
                      messengerWrapper.verifySender(msg.sender, msg.data);
                      _;
                  }
                  constructor (address[] memory bonders, address _governance) public Bridge(bonders) {
                      governance = _governance;
                  }
                  /* ========== Send Functions ========== */
                  /**
                   * @notice `amountOutMin` and `deadline` should be 0 when no swap is intended at the destination.
                   * @notice `amount` is the total amount the user wants to send including the relayer fee
                   * @dev Send tokens to a supported layer-2 to mint hToken and optionally swap the hToken in the
                   * AMM at the destination.
                   * @param chainId The chainId of the destination chain
                   * @param recipient The address receiving funds at the destination
                   * @param amount The amount being sent
                   * @param amountOutMin The minimum amount received after attempting to swap in the destination
                   * AMM market. 0 if no swap is intended.
                   * @param deadline The deadline for swapping in the destination AMM market. 0 if no
                   * swap is intended.
                   * @param relayer The address of the relayer at the destination.
                   * @param relayerFee The amount distributed to the relayer at the destination. This is subtracted from the `amount`.
                   */
                  function sendToL2(
                      uint256 chainId,
                      address recipient,
                      uint256 amount,
                      uint256 amountOutMin,
                      uint256 deadline,
                      address relayer,
                      uint256 relayerFee
                  )
                      external
                      payable
                  {
                      IMessengerWrapper messengerWrapper = crossDomainMessengerWrappers[chainId];
                      require(messengerWrapper != IMessengerWrapper(0), "L1_BRG: chainId not supported");
                      require(isChainIdPaused[chainId] == false, "L1_BRG: Sends to this chainId are paused");
                      require(amount > 0, "L1_BRG: Must transfer a non-zero amount");
                      require(amount >= relayerFee, "L1_BRG: Relayer fee cannot exceed amount");
                      _transferToBridge(msg.sender, amount);
                      bytes memory message = abi.encodeWithSignature(
                          "distribute(address,uint256,uint256,uint256,address,uint256)",
                          recipient,
                          amount,
                          amountOutMin,
                          deadline,
                          relayer,
                          relayerFee
                      );
                      chainBalance[chainId] = chainBalance[chainId].add(amount);
                      messengerWrapper.sendCrossDomainMessage(message);
                      emit TransferSentToL2(
                          chainId,
                          recipient,
                          amount,
                          amountOutMin,
                          deadline,
                          relayer,
                          relayerFee
                      );
                  }
                  /* ========== TransferRoot Functions ========== */
                  /**
                   * @dev Setting a TransferRoot is a two step process.
                   * @dev   1. The TransferRoot is bonded with `bondTransferRoot`. Withdrawals can now begin on L1
                   * @dev      and recipient L2's
                   * @dev   2. The TransferRoot is confirmed after `confirmTransferRoot` is called by the l2 bridge
                   * @dev      where the TransferRoot originated.
                   */
                  /**
                   * @dev Used by the Bonder to bond a TransferRoot and propagate it up to destination L2s
                   * @param rootHash The Merkle root of the TransferRoot Merkle tree
                   * @param destinationChainId The id of the destination chain
                   * @param totalAmount The amount destined for the destination chain
                   */
                  function bondTransferRoot(
                      bytes32 rootHash,
                      uint256 destinationChainId,
                      uint256 totalAmount
                  )
                      external
                      onlyBonder
                      requirePositiveBalance
                  {
                      bytes32 transferRootId = getTransferRootId(rootHash, totalAmount);
                      require(transferRootCommittedAt[destinationChainId][transferRootId] == 0, "L1_BRG: TransferRoot has already been confirmed");
                      require(transferBonds[transferRootId].createdAt == 0, "L1_BRG: TransferRoot has already been bonded");
                      uint256 currentTimeSlot = getTimeSlot(block.timestamp);
                      uint256 bondAmount = getBondForTransferAmount(totalAmount);
                      timeSlotToAmountBonded[currentTimeSlot][msg.sender] = timeSlotToAmountBonded[currentTimeSlot][msg.sender].add(bondAmount);
                      transferBonds[transferRootId] = TransferBond(
                          msg.sender,
                          block.timestamp,
                          totalAmount,
                          uint256(0),
                          address(0),
                          false
                      );
                      _distributeTransferRoot(rootHash, destinationChainId, totalAmount);
                      emit TransferRootBonded(rootHash, totalAmount);
                  }
                  /**
                   * @dev Used by an L2 bridge to confirm a TransferRoot via cross-domain message. Once a TransferRoot
                   * has been confirmed, any challenge against that TransferRoot can be resolved as unsuccessful.
                   * @param originChainId The id of the origin chain
                   * @param rootHash The Merkle root of the TransferRoot Merkle tree
                   * @param destinationChainId The id of the destination chain
                   * @param totalAmount The amount destined for each destination chain
                   * @param rootCommittedAt The block timestamp when the TransferRoot was committed on its origin chain
                   */
                  function confirmTransferRoot(
                      uint256 originChainId,
                      bytes32 rootHash,
                      uint256 destinationChainId,
                      uint256 totalAmount,
                      uint256 rootCommittedAt
                  )
                      external
                      onlyL2Bridge(originChainId)
                  {
                      bytes32 transferRootId = getTransferRootId(rootHash, totalAmount);
                      require(transferRootCommittedAt[destinationChainId][transferRootId] == 0, "L1_BRG: TransferRoot already confirmed");
                      require(rootCommittedAt > 0, "L1_BRG: rootCommittedAt must be greater than 0");
                      transferRootCommittedAt[destinationChainId][transferRootId] = rootCommittedAt;
                      chainBalance[originChainId] = chainBalance[originChainId].sub(totalAmount, "L1_BRG: Amount exceeds chainBalance. This indicates a layer-2 failure.");
                      // If the TransferRoot was never bonded, distribute the TransferRoot.
                      TransferBond storage transferBond = transferBonds[transferRootId];
                      if (transferBond.createdAt == 0) {
                          _distributeTransferRoot(rootHash, destinationChainId, totalAmount);
                      }
                      emit TransferRootConfirmed(originChainId, destinationChainId, rootHash, totalAmount);
                  }
                  function _distributeTransferRoot(
                      bytes32 rootHash,
                      uint256 chainId,
                      uint256 totalAmount
                  )
                      internal
                  {
                      // Set TransferRoot on recipient Bridge
                      if (chainId == getChainId()) {
                          // Set L1 TransferRoot
                          _setTransferRoot(rootHash, totalAmount);
                      } else {
                          chainBalance[chainId] = chainBalance[chainId].add(totalAmount);
                          IMessengerWrapper messengerWrapper = crossDomainMessengerWrappers[chainId];
                          require(messengerWrapper != IMessengerWrapper(0), "L1_BRG: chainId not supported");
                          // Set L2 TransferRoot
                          bytes memory setTransferRootMessage = abi.encodeWithSignature(
                              "setTransferRoot(bytes32,uint256)",
                              rootHash,
                              totalAmount
                          );
                          messengerWrapper.sendCrossDomainMessage(setTransferRootMessage);
                      }
                  }
                  /* ========== External TransferRoot Challenges ========== */
                  /**
                   * @dev Challenge a TransferRoot believed to be fraudulent
                   * @param rootHash The Merkle root of the TransferRoot Merkle tree
                   * @param originalAmount The total amount bonded for this TransferRoot
                   * @param destinationChainId The id of the destination chain
                   */
                  function challengeTransferBond(bytes32 rootHash, uint256 originalAmount, uint256 destinationChainId) external payable {
                      bytes32 transferRootId = getTransferRootId(rootHash, originalAmount);
                      TransferBond storage transferBond = transferBonds[transferRootId];
                      require(transferRootCommittedAt[destinationChainId][transferRootId] == 0, "L1_BRG: TransferRoot has already been confirmed");
                      require(transferBond.createdAt != 0, "L1_BRG: TransferRoot has not been bonded");
                      uint256 challengePeriodEnd = transferBond.createdAt.add(challengePeriod);
                      require(challengePeriodEnd >= block.timestamp, "L1_BRG: TransferRoot cannot be challenged after challenge period");
                      require(transferBond.challengeStartTime == 0, "L1_BRG: TransferRoot already challenged");
                      transferBond.challengeStartTime = block.timestamp;
                      transferBond.challenger = msg.sender;
                      // Move amount from timeSlotToAmountBonded to debit
                      uint256 timeSlot = getTimeSlot(transferBond.createdAt);
                      uint256 bondAmount = getBondForTransferAmount(originalAmount);
                      address bonder = transferBond.bonder;
                      timeSlotToAmountBonded[timeSlot][bonder] = timeSlotToAmountBonded[timeSlot][bonder].sub(bondAmount);
                      _addDebit(transferBond.bonder, bondAmount);
                      // Get stake for challenge
                      uint256 challengeStakeAmount = getChallengeAmountForTransferAmount(originalAmount);
                      _transferToBridge(msg.sender, challengeStakeAmount);
                      emit TransferBondChallenged(transferRootId, rootHash, originalAmount);
                  }
                  /**
                   * @dev Resolve a challenge after the `challengeResolutionPeriod` has passed
                   * @param rootHash The Merkle root of the TransferRoot Merkle tree
                   * @param originalAmount The total amount originally bonded for this TransferRoot
                   * @param destinationChainId The id of the destination chain
                   */
                  function resolveChallenge(bytes32 rootHash, uint256 originalAmount, uint256 destinationChainId) external {
                      bytes32 transferRootId = getTransferRootId(rootHash, originalAmount);
                      TransferBond storage transferBond = transferBonds[transferRootId];
                      require(transferBond.challengeStartTime != 0, "L1_BRG: TransferRoot has not been challenged");
                      require(block.timestamp > transferBond.challengeStartTime.add(challengeResolutionPeriod), "L1_BRG: Challenge period has not ended");
                      require(transferBond.challengeResolved == false, "L1_BRG: TransferRoot already resolved");
                      transferBond.challengeResolved = true;
                      uint256 challengeStakeAmount = getChallengeAmountForTransferAmount(originalAmount);
                      if (transferRootCommittedAt[destinationChainId][transferRootId] > 0) {
                          // Invalid challenge
                          if (transferBond.createdAt > transferRootCommittedAt[destinationChainId][transferRootId].add(minTransferRootBondDelay)) {
                              // Credit the bonder back with the bond amount plus the challenger's stake
                              _addCredit(transferBond.bonder, getBondForTransferAmount(originalAmount).add(challengeStakeAmount));
                          } else {
                              // If the TransferRoot was bonded before it was committed, the challenger and Bonder
                              // get their stake back. This discourages Bonders from tricking challengers into
                              // challenging a valid TransferRoots that haven't yet been committed. It also ensures
                              // that Bonders are not punished if a TransferRoot is bonded too soon in error.
                              // Return the challenger's stake
                              _addCredit(transferBond.challenger, challengeStakeAmount);
                              // Credit the bonder back with the bond amount
                              _addCredit(transferBond.bonder, getBondForTransferAmount(originalAmount));
                          }
                      } else {
                          // Valid challenge
                          // Burn 25% of the challengers stake
                          _transferFromBridge(address(0xdead), challengeStakeAmount.mul(1).div(4));
                          // Reward challenger with the remaining 75% of their stake plus 100% of the Bonder's stake
                          _addCredit(transferBond.challenger, challengeStakeAmount.mul(7).div(4));
                      }
                      emit ChallengeResolved(transferRootId, rootHash, originalAmount);
                  }
                  /* ========== Override Functions ========== */
                  function _additionalDebit(address bonder) internal view override returns (uint256) {
                      uint256 currentTimeSlot = getTimeSlot(block.timestamp);
                      uint256 bonded = 0;
                      uint256 numTimeSlots = challengePeriod / TIME_SLOT_SIZE;
                      for (uint256 i = 0; i < numTimeSlots; i++) {
                          bonded = bonded.add(timeSlotToAmountBonded[currentTimeSlot - i][bonder]);
                      }
                      return bonded;
                  }
                  function _requireIsGovernance() internal override {
                      require(governance == msg.sender, "L1_BRG: Caller is not the owner");
                  }
                  /* ========== External Config Management Setters ========== */
                  function setGovernance(address _newGovernance) external onlyGovernance {
                      require(_newGovernance != address(0), "L1_BRG: _newGovernance cannot be address(0)");
                      governance = _newGovernance;
                  }
                  function setCrossDomainMessengerWrapper(uint256 chainId, IMessengerWrapper _crossDomainMessengerWrapper) external onlyGovernance {
                      crossDomainMessengerWrappers[chainId] = _crossDomainMessengerWrapper;
                  }
                  function setChainIdDepositsPaused(uint256 chainId, bool isPaused) external onlyGovernance {
                      isChainIdPaused[chainId] = isPaused;
                  }
                  function setChallengePeriod(uint256 _challengePeriod) external onlyGovernance {
                      require(_challengePeriod % TIME_SLOT_SIZE == 0, "L1_BRG: challengePeriod must be divisible by TIME_SLOT_SIZE");
                      challengePeriod = _challengePeriod;
                  }
                  function setChallengeResolutionPeriod(uint256 _challengeResolutionPeriod) external onlyGovernance {
                      challengeResolutionPeriod = _challengeResolutionPeriod;
                  }
                  function setMinTransferRootBondDelay(uint256 _minTransferRootBondDelay) external onlyGovernance {
                      minTransferRootBondDelay = _minTransferRootBondDelay;
                  }
                  /* ========== Public Getters ========== */
                  function getBondForTransferAmount(uint256 amount) public pure returns (uint256) {
                      // Bond covers amount plus a bounty to pay a potential challenger
                      return amount.add(getChallengeAmountForTransferAmount(amount));
                  }
                  function getChallengeAmountForTransferAmount(uint256 amount) public pure returns (uint256) {
                      // Bond covers amount plus a bounty to pay a potential challenger
                      return amount.div(CHALLENGE_AMOUNT_DIVISOR);
                  }
                  function getTimeSlot(uint256 time) public pure returns (uint256) {
                      return time / TIME_SLOT_SIZE;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity 0.6.12;
              pragma experimental ABIEncoderV2;
              import "./Accounting.sol";
              import "../libraries/Lib_MerkleTree.sol";
              /**
               * @dev Bridge extends the accounting system and encapsulates the logic that is shared by both the
               * L1 and L2 Bridges. It allows to TransferRoots to be set by parent contracts and for those
               * TransferRoots to be withdrawn against. It also allows the bonder to bond and withdraw Transfers
               * directly through `bondWithdrawal` and then settle those bonds against their TransferRoot once it
               * has been set.
               */
              abstract contract Bridge is Accounting {
                  using Lib_MerkleTree for bytes32;
                  struct TransferRoot {
                      uint256 total;
                      uint256 amountWithdrawn;
                      uint256 createdAt;
                  }
                  /* ========== Events ========== */
                  event Withdrew(
                      bytes32 indexed transferId,
                      address indexed recipient,
                      uint256 amount,
                      bytes32 transferNonce
                  );
                  event WithdrawalBonded(
                      bytes32 indexed transferId,
                      uint256 amount
                  );
                  event WithdrawalBondSettled(
                      address indexed bonder,
                      bytes32 indexed transferId,
                      bytes32 indexed rootHash
                  );
                  event MultipleWithdrawalsSettled(
                      address indexed bonder,
                      bytes32 indexed rootHash,
                      uint256 totalBondsSettled
                  );
                  event TransferRootSet(
                      bytes32 indexed rootHash,
                      uint256 totalAmount
                  );
                  /* ========== State ========== */
                  mapping(bytes32 => TransferRoot) private _transferRoots;
                  mapping(bytes32 => bool) private _spentTransferIds;
                  mapping(address => mapping(bytes32 => uint256)) private _bondedWithdrawalAmounts;
                  uint256 constant RESCUE_DELAY = 8 weeks;
                  constructor(address[] memory bonders) public Accounting(bonders) {}
                  /* ========== Public Getters ========== */
                  /**
                   * @dev Get the hash that represents an individual Transfer.
                   * @param chainId The id of the destination chain
                   * @param recipient The address receiving the Transfer
                   * @param amount The amount being transferred including the `_bonderFee`
                   * @param transferNonce Used to avoid transferId collisions
                   * @param bonderFee The amount paid to the address that withdraws the Transfer
                   * @param amountOutMin The minimum amount received after attempting to swap in the destination
                   * AMM market. 0 if no swap is intended.
                   * @param deadline The deadline for swapping in the destination AMM market. 0 if no
                   * swap is intended.
                   */
                  function getTransferId(
                      uint256 chainId,
                      address recipient,
                      uint256 amount,
                      bytes32 transferNonce,
                      uint256 bonderFee,
                      uint256 amountOutMin,
                      uint256 deadline
                  )
                      public
                      pure
                      returns (bytes32)
                  {
                      return keccak256(abi.encode(
                          chainId,
                          recipient,
                          amount,
                          transferNonce,
                          bonderFee,
                          amountOutMin,
                          deadline
                      ));
                  }
                  /**
                   * @notice getChainId can be overridden by subclasses if needed for compatibility or testing purposes.
                   * @dev Get the current chainId
                   * @return chainId The current chainId
                   */
                  function getChainId() public virtual view returns (uint256 chainId) {
                      this; // Silence state mutability warning without generating any additional byte code
                      assembly {
                          chainId := chainid()
                      }
                  }
                  /**
                   * @dev Get the TransferRoot id for a given rootHash and totalAmount
                   * @param rootHash The Merkle root of the TransferRoot
                   * @param totalAmount The total of all Transfers in the TransferRoot
                   * @return The calculated transferRootId
                   */
                  function getTransferRootId(bytes32 rootHash, uint256 totalAmount) public pure returns (bytes32) {
                      return keccak256(abi.encodePacked(rootHash, totalAmount));
                  }
                  /**
                   * @dev Get the TransferRoot for a given rootHash and totalAmount
                   * @param rootHash The Merkle root of the TransferRoot
                   * @param totalAmount The total of all Transfers in the TransferRoot
                   * @return The TransferRoot with the calculated transferRootId
                   */
                  function getTransferRoot(bytes32 rootHash, uint256 totalAmount) public view returns (TransferRoot memory) {
                      return _transferRoots[getTransferRootId(rootHash, totalAmount)];
                  }
                  /**
                   * @dev Get the amount bonded for the withdrawal of a transfer
                   * @param bonder The Bonder of the withdrawal
                   * @param transferId The Transfer's unique identifier
                   * @return The amount bonded for a Transfer withdrawal
                   */
                  function getBondedWithdrawalAmount(address bonder, bytes32 transferId) external view returns (uint256) {
                      return _bondedWithdrawalAmounts[bonder][transferId];
                  }
                  /**
                   * @dev Get the spent status of a transfer ID
                   * @param transferId The transfer's unique identifier
                   * @return True if the transferId has been spent
                   */
                  function isTransferIdSpent(bytes32 transferId) external view returns (bool) {
                      return _spentTransferIds[transferId];
                  }
                  /* ========== User/Relayer External Functions ========== */
                  /**
                   * @notice Can be called by anyone (recipient or relayer)
                   * @dev Withdraw a Transfer from its destination bridge
                   * @param recipient The address receiving the Transfer
                   * @param amount The amount being transferred including the `_bonderFee`
                   * @param transferNonce Used to avoid transferId collisions
                   * @param bonderFee The amount paid to the address that withdraws the Transfer
                   * @param amountOutMin The minimum amount received after attempting to swap in the destination
                   * AMM market. 0 if no swap is intended. (only used to calculate `transferId` in this function)
                   * @param deadline The deadline for swapping in the destination AMM market. 0 if no
                   * swap is intended. (only used to calculate `transferId` in this function)
                   * @param rootHash The Merkle root of the TransferRoot
                   * @param transferRootTotalAmount The total amount being transferred in a TransferRoot
                   * @param transferIdTreeIndex The index of the transferId in the Merkle tree
                   * @param siblings The siblings of the transferId in the Merkle tree
                   * @param totalLeaves The total number of leaves in the Merkle tree
                   */
                  function withdraw(
                      address recipient,
                      uint256 amount,
                      bytes32 transferNonce,
                      uint256 bonderFee,
                      uint256 amountOutMin,
                      uint256 deadline,
                      bytes32 rootHash,
                      uint256 transferRootTotalAmount,
                      uint256 transferIdTreeIndex,
                      bytes32[] calldata siblings,
                      uint256 totalLeaves
                  )
                      external
                      nonReentrant
                  {
                      bytes32 transferId = getTransferId(
                          getChainId(),
                          recipient,
                          amount,
                          transferNonce,
                          bonderFee,
                          amountOutMin,
                          deadline
                      );
                      require(
                          rootHash.verify(
                              transferId,
                              transferIdTreeIndex,
                              siblings,
                              totalLeaves
                          )
                      , "BRG: Invalid transfer proof");
                      bytes32 transferRootId = getTransferRootId(rootHash, transferRootTotalAmount);
                      _addToAmountWithdrawn(transferRootId, amount);
                      _fulfillWithdraw(transferId, recipient, amount, uint256(0));
                      emit Withdrew(transferId, recipient, amount, transferNonce);
                  }
                  /**
                   * @dev Allows the bonder to bond individual withdrawals before their TransferRoot has been committed.
                   * @param recipient The address receiving the Transfer
                   * @param amount The amount being transferred including the `_bonderFee`
                   * @param transferNonce Used to avoid transferId collisions
                   * @param bonderFee The amount paid to the address that withdraws the Transfer
                   */
                  function bondWithdrawal(
                      address recipient,
                      uint256 amount,
                      bytes32 transferNonce,
                      uint256 bonderFee
                  )
                      external
                      onlyBonder
                      requirePositiveBalance
                      nonReentrant
                  {
                      bytes32 transferId = getTransferId(
                          getChainId(),
                          recipient,
                          amount,
                          transferNonce,
                          bonderFee,
                          0,
                          0
                      );
                      _bondWithdrawal(transferId, amount);
                      _fulfillWithdraw(transferId, recipient, amount, bonderFee);
                  }
                  /**
                   * @dev Refunds the Bonder's stake from a bonded withdrawal and counts that withdrawal against
                   * its TransferRoot.
                   * @param bonder The Bonder of the withdrawal
                   * @param transferId The Transfer's unique identifier
                   * @param rootHash The Merkle root of the TransferRoot
                   * @param transferRootTotalAmount The total amount being transferred in a TransferRoot
                   * @param transferIdTreeIndex The index of the transferId in the Merkle tree
                   * @param siblings The siblings of the transferId in the Merkle tree
                   * @param totalLeaves The total number of leaves in the Merkle tree
                   */
                  function settleBondedWithdrawal(
                      address bonder,
                      bytes32 transferId,
                      bytes32 rootHash,
                      uint256 transferRootTotalAmount,
                      uint256 transferIdTreeIndex,
                      bytes32[] calldata siblings,
                      uint256 totalLeaves
                  )
                      external
                  {
                      require(
                          rootHash.verify(
                              transferId,
                              transferIdTreeIndex,
                              siblings,
                              totalLeaves
                          )
                      , "BRG: Invalid transfer proof");
                      bytes32 transferRootId = getTransferRootId(rootHash, transferRootTotalAmount);
                      uint256 amount = _bondedWithdrawalAmounts[bonder][transferId];
                      require(amount > 0, "L2_BRG: transferId has no bond");
                      _bondedWithdrawalAmounts[bonder][transferId] = 0;
                      _addToAmountWithdrawn(transferRootId, amount);
                      _addCredit(bonder, amount);
                      emit WithdrawalBondSettled(bonder, transferId, rootHash);
                  }
                  /**
                   * @dev Refunds the Bonder for all withdrawals that they bonded in a TransferRoot.
                   * @param bonder The address of the Bonder being refunded
                   * @param transferIds All transferIds in the TransferRoot in order
                   * @param totalAmount The totalAmount of the TransferRoot
                   */
                  function settleBondedWithdrawals(
                      address bonder,
                      // transferIds _must_ be calldata or it will be mutated by Lib_MerkleTree.getMerkleRoot
                      bytes32[] calldata transferIds,
                      uint256 totalAmount
                  )
                      external
                  {
                      bytes32 rootHash = Lib_MerkleTree.getMerkleRoot(transferIds);
                      bytes32 transferRootId = getTransferRootId(rootHash, totalAmount);
                      uint256 totalBondsSettled = 0;
                      for(uint256 i = 0; i < transferIds.length; i++) {
                          uint256 transferBondAmount = _bondedWithdrawalAmounts[bonder][transferIds[i]];
                          if (transferBondAmount > 0) {
                              totalBondsSettled = totalBondsSettled.add(transferBondAmount);
                              _bondedWithdrawalAmounts[bonder][transferIds[i]] = 0;
                          }
                      }
                      _addToAmountWithdrawn(transferRootId, totalBondsSettled);
                      _addCredit(bonder, totalBondsSettled);
                      emit MultipleWithdrawalsSettled(bonder, rootHash, totalBondsSettled);
                  }
                  /* ========== External TransferRoot Rescue ========== */
                  /**
                   * @dev Allows governance to withdraw the remaining amount from a TransferRoot after the rescue delay has passed.
                   * @param rootHash the Merkle root of the TransferRoot
                   * @param originalAmount The TransferRoot's recorded total
                   * @param recipient The address receiving the remaining balance
                   */
                  function rescueTransferRoot(bytes32 rootHash, uint256 originalAmount, address recipient) external onlyGovernance {
                      bytes32 transferRootId = getTransferRootId(rootHash, originalAmount);
                      TransferRoot memory transferRoot = getTransferRoot(rootHash, originalAmount);
                      require(transferRoot.createdAt != 0, "BRG: TransferRoot not found");
                      assert(transferRoot.total == originalAmount);
                      uint256 rescueDelayEnd = transferRoot.createdAt.add(RESCUE_DELAY);
                      require(block.timestamp >= rescueDelayEnd, "BRG: TransferRoot cannot be rescued before the Rescue Delay");
                      uint256 remainingAmount = transferRoot.total.sub(transferRoot.amountWithdrawn);
                      _addToAmountWithdrawn(transferRootId, remainingAmount);
                      _transferFromBridge(recipient, remainingAmount);
                  }
                  /* ========== Internal Functions ========== */
                  function _markTransferSpent(bytes32 transferId) internal {
                      require(!_spentTransferIds[transferId], "BRG: The transfer has already been withdrawn");
                      _spentTransferIds[transferId] = true;
                  }
                  function _addToAmountWithdrawn(bytes32 transferRootId, uint256 amount) internal {
                      TransferRoot storage transferRoot = _transferRoots[transferRootId];
                      require(transferRoot.total > 0, "BRG: Transfer root not found");
                      uint256 newAmountWithdrawn = transferRoot.amountWithdrawn.add(amount);
                      require(newAmountWithdrawn <= transferRoot.total, "BRG: Withdrawal exceeds TransferRoot total");
                      transferRoot.amountWithdrawn = newAmountWithdrawn;
                  }
                  function _setTransferRoot(bytes32 rootHash, uint256 totalAmount) internal {
                      bytes32 transferRootId = getTransferRootId(rootHash, totalAmount);
                      require(_transferRoots[transferRootId].total == 0, "BRG: Transfer root already set");
                      require(totalAmount > 0, "BRG: Cannot set TransferRoot totalAmount of 0");
                      _transferRoots[transferRootId] = TransferRoot(totalAmount, 0, block.timestamp);
                      emit TransferRootSet(rootHash, totalAmount);
                  }
                  function _bondWithdrawal(bytes32 transferId, uint256 amount) internal {
                      require(_bondedWithdrawalAmounts[msg.sender][transferId] == 0, "BRG: Withdrawal has already been bonded");
                      _addDebit(msg.sender, amount);
                      _bondedWithdrawalAmounts[msg.sender][transferId] = amount;
                      emit WithdrawalBonded(transferId, amount);
                  }
                  /* ========== Private Functions ========== */
                  /// @dev Completes the Transfer, distributes the Bonder fee and marks the Transfer as spent.
                  function _fulfillWithdraw(
                      bytes32 transferId,
                      address recipient,
                      uint256 amount,
                      uint256 bonderFee
                  ) private {
                      _markTransferSpent(transferId);
                      _transferFromBridge(recipient, amount.sub(bonderFee));
                      if (bonderFee > 0) {
                          _transferFromBridge(msg.sender, bonderFee);
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.12 <0.8.0;
              pragma experimental ABIEncoderV2;
              interface IMessengerWrapper {
                  function sendCrossDomainMessage(bytes memory _calldata) external;
                  function verifySender(address l1BridgeCaller, bytes memory _data) external;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity 0.6.12;
              pragma experimental ABIEncoderV2;
              import "@openzeppelin/contracts/math/SafeMath.sol";
              import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
              /**
               * @dev Accounting is an abstract contract that encapsulates the most critical logic in the Hop contracts.
               * The accounting system works by using two balances that can only increase `_credit` and `_debit`.
               * A bonder's available balance is the total credit minus the total debit. The contract exposes
               * two external functions that allows a bonder to stake and unstake and exposes two internal
               * functions to its child contracts that allow the child contract to add to the credit 
               * and debit balance. In addition, child contracts can override `_additionalDebit` to account
               * for any additional debit balance in an alternative way. Lastly, it exposes a modifier,
               * `requirePositiveBalance`, that can be used by child contracts to ensure the bonder does not
               * use more than its available stake.
               */
              abstract contract Accounting is ReentrancyGuard {
                  using SafeMath for uint256;
                  mapping(address => bool) private _isBonder;
                  mapping(address => uint256) private _credit;
                  mapping(address => uint256) private _debit;
                  event Stake (
                      address indexed account,
                      uint256 amount
                  );
                  event Unstake (
                      address indexed account,
                      uint256 amount
                  );
                  event BonderAdded (
                      address indexed newBonder
                  );
                  event BonderRemoved (
                      address indexed previousBonder
                  );
                  /* ========== Modifiers ========== */
                  modifier onlyBonder {
                      require(_isBonder[msg.sender], "ACT: Caller is not bonder");
                      _;
                  }
                  modifier onlyGovernance {
                      _requireIsGovernance();
                      _;
                  }
                  /// @dev Used by parent contract to ensure that the Bonder is solvent at the end of the transaction.
                  modifier requirePositiveBalance {
                      _;
                      require(getCredit(msg.sender) >= getDebitAndAdditionalDebit(msg.sender), "ACT: Not enough available credit");
                  }
                  /// @dev Sets the Bonder addresses
                  constructor(address[] memory bonders) public {
                      for (uint256 i = 0; i < bonders.length; i++) {
                          require(_isBonder[bonders[i]] == false, "ACT: Cannot add duplicate bonder");
                          _isBonder[bonders[i]] = true;
                          emit BonderAdded(bonders[i]);
                      }
                  }
                  /* ========== Virtual functions ========== */
                  /**
                   * @dev The following functions are overridden in L1_Bridge and L2_Bridge
                   */
                  function _transferFromBridge(address recipient, uint256 amount) internal virtual;
                  function _transferToBridge(address from, uint256 amount) internal virtual;
                  function _requireIsGovernance() internal virtual;
                  /**
                   * @dev This function can be optionally overridden by a parent contract to track any additional
                   * debit balance in an alternative way.
                   */
                  function _additionalDebit(address /*bonder*/) internal view virtual returns (uint256) {
                      this; // Silence state mutability warning without generating any additional byte code
                      return 0;
                  }
                  /* ========== Public/external getters ========== */
                  /**
                   * @dev Check if address is a Bonder
                   * @param maybeBonder The address being checked
                   * @return true if address is a Bonder
                   */
                  function getIsBonder(address maybeBonder) public view returns (bool) {
                      return _isBonder[maybeBonder];
                  }
                  /**
                   * @dev Get the Bonder's credit balance
                   * @param bonder The owner of the credit balance being checked
                   * @return The credit balance for the Bonder
                   */
                  function getCredit(address bonder) public view returns (uint256) {
                      return _credit[bonder];
                  }
                  /**
                   * @dev Gets the debit balance tracked by `_debit` and does not include `_additionalDebit()`
                   * @param bonder The owner of the debit balance being checked
                   * @return The debit amount for the Bonder
                   */
                  function getRawDebit(address bonder) external view returns (uint256) {
                      return _debit[bonder];
                  }
                  /**
                   * @dev Get the Bonder's total debit
                   * @param bonder The owner of the debit balance being checked
                   * @return The Bonder's total debit balance
                   */
                  function getDebitAndAdditionalDebit(address bonder) public view returns (uint256) {
                      return _debit[bonder].add(_additionalDebit(bonder));
                  }
                  /* ========== Bonder external functions ========== */
                  /** 
                   * @dev Allows the Bonder to deposit tokens and increase its credit balance
                   * @param bonder The address being staked on
                   * @param amount The amount being staked
                   */
                  function stake(address bonder, uint256 amount) external payable nonReentrant {
                      require(_isBonder[bonder] == true, "ACT: Address is not bonder");
                      _transferToBridge(msg.sender, amount);
                      _addCredit(bonder, amount);
                      emit Stake(bonder, amount);
                  }
                  /**
                   * @dev Allows the caller to withdraw any available balance and add to their debit balance
                   * @param amount The amount being unstaked
                   */
                  function unstake(uint256 amount) external requirePositiveBalance nonReentrant {
                      _addDebit(msg.sender, amount);
                      _transferFromBridge(msg.sender, amount);
                      emit Unstake(msg.sender, amount);
                  }
                  /**
                   * @dev Add Bonder to allowlist
                   * @param bonder The address being added as a Bonder
                   */
                  function addBonder(address bonder) external onlyGovernance {
                      require(_isBonder[bonder] == false, "ACT: Address is already bonder");
                      _isBonder[bonder] = true;
                      emit BonderAdded(bonder);
                  }
                  /**
                   * @dev Remove Bonder from allowlist
                   * @param bonder The address being removed as a Bonder
                   */
                  function removeBonder(address bonder) external onlyGovernance {
                      require(_isBonder[bonder] == true, "ACT: Address is not bonder");
                      _isBonder[bonder] = false;
                      emit BonderRemoved(bonder);
                  }
                  /* ========== Internal functions ========== */
                  function _addCredit(address bonder, uint256 amount) internal {
                      _credit[bonder] = _credit[bonder].add(amount);
                  }
                  function _addDebit(address bonder, uint256 amount) internal {
                      _debit[bonder] = _debit[bonder].add(amount);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.8.0;
              /**
               * @title Lib_MerkleTree
               * @author River Keefer
               */
              library Lib_MerkleTree {
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Calculates a merkle root for a list of 32-byte leaf hashes.  WARNING: If the number
                   * of leaves passed in is not a power of two, it pads out the tree with zero hashes.
                   * If you do not know the original length of elements for the tree you are verifying,
                   * then this may allow empty leaves past _elements.length to pass a verification check down the line.
                   * Note that the _elements argument is modified, therefore it must not be used again afterwards
                   * @param _elements Array of hashes from which to generate a merkle root.
                   * @return Merkle root of the leaves, with zero hashes for non-powers-of-two (see above).
                   */
                  function getMerkleRoot(
                      bytes32[] memory _elements
                  )
                      internal
                      pure
                      returns (
                          bytes32
                      )
                  {
                      require(
                          _elements.length > 0,
                          "Lib_MerkleTree: Must provide at least one leaf hash."
                      );
                      if (_elements.length == 1) {
                          return _elements[0];
                      }
                      uint256[16] memory defaults = [
                          0x290decd9548b62a8d60345a988386fc84ba6bc95484008f6362f93160ef3e563,
                          0x633dc4d7da7256660a892f8f1604a44b5432649cc8ec5cb3ced4c4e6ac94dd1d,
                          0x890740a8eb06ce9be422cb8da5cdafc2b58c0a5e24036c578de2a433c828ff7d,
                          0x3b8ec09e026fdc305365dfc94e189a81b38c7597b3d941c279f042e8206e0bd8,
                          0xecd50eee38e386bd62be9bedb990706951b65fe053bd9d8a521af753d139e2da,
                          0xdefff6d330bb5403f63b14f33b578274160de3a50df4efecf0e0db73bcdd3da5,
                          0x617bdd11f7c0a11f49db22f629387a12da7596f9d1704d7465177c63d88ec7d7,
                          0x292c23a9aa1d8bea7e2435e555a4a60e379a5a35f3f452bae60121073fb6eead,
                          0xe1cea92ed99acdcb045a6726b2f87107e8a61620a232cf4d7d5b5766b3952e10,
                          0x7ad66c0a68c72cb89e4fb4303841966e4062a76ab97451e3b9fb526a5ceb7f82,
                          0xe026cc5a4aed3c22a58cbd3d2ac754c9352c5436f638042dca99034e83636516,
                          0x3d04cffd8b46a874edf5cfae63077de85f849a660426697b06a829c70dd1409c,
                          0xad676aa337a485e4728a0b240d92b3ef7b3c372d06d189322bfd5f61f1e7203e,
                          0xa2fca4a49658f9fab7aa63289c91b7c7b6c832a6d0e69334ff5b0a3483d09dab,
                          0x4ebfd9cd7bca2505f7bef59cc1c12ecc708fff26ae4af19abe852afe9e20c862,
                          0x2def10d13dd169f550f578bda343d9717a138562e0093b380a1120789d53cf10
                      ];
                      // Reserve memory space for our hashes.
                      bytes memory buf = new bytes(64);
                      // We'll need to keep track of left and right siblings.
                      bytes32 leftSibling;
                      bytes32 rightSibling;
                      // Number of non-empty nodes at the current depth.
                      uint256 rowSize = _elements.length;
                      // Current depth, counting from 0 at the leaves
                      uint256 depth = 0;
                      // Common sub-expressions
                      uint256 halfRowSize;         // rowSize / 2
                      bool rowSizeIsOdd;           // rowSize % 2 == 1
                      while (rowSize > 1) {
                          halfRowSize = rowSize / 2;
                          rowSizeIsOdd = rowSize % 2 == 1;
                          for (uint256 i = 0; i < halfRowSize; i++) {
                              leftSibling  = _elements[(2 * i)    ];
                              rightSibling = _elements[(2 * i) + 1];
                              assembly {
                                  mstore(add(buf, 32), leftSibling )
                                  mstore(add(buf, 64), rightSibling)
                              }
                              _elements[i] = keccak256(buf);
                          }
                          if (rowSizeIsOdd) {
                              leftSibling  = _elements[rowSize - 1];
                              rightSibling = bytes32(defaults[depth]);
                              assembly {
                                  mstore(add(buf, 32), leftSibling)
                                  mstore(add(buf, 64), rightSibling)
                              }
                              _elements[halfRowSize] = keccak256(buf);
                          }
                          rowSize = halfRowSize + (rowSizeIsOdd ? 1 : 0);
                          depth++;
                      }
                      return _elements[0];
                  }
                  /**
                   * Verifies a merkle branch for the given leaf hash.  Assumes the original length
                   * of leaves generated is a known, correct input, and does not return true for indices
                   * extending past that index (even if _siblings would be otherwise valid.)
                   * @param _root The Merkle root to verify against.
                   * @param _leaf The leaf hash to verify inclusion of.
                   * @param _index The index in the tree of this leaf.
                   * @param _siblings Array of sibline nodes in the inclusion proof, starting from depth 0 (bottom of the tree).
                   * @param _totalLeaves The total number of leaves originally passed into.
                   * @return Whether or not the merkle branch and leaf passes verification.
                   */
                  function verify(
                      bytes32 _root,
                      bytes32 _leaf,
                      uint256 _index,
                      bytes32[] memory _siblings,
                      uint256 _totalLeaves
                  )
                      internal
                      pure
                      returns (
                          bool
                      )
                  {
                      require(
                          _totalLeaves > 0,
                          "Lib_MerkleTree: Total leaves must be greater than zero."
                      );
                      require(
                          _index < _totalLeaves,
                          "Lib_MerkleTree: Index out of bounds."
                      );
                      require(
                          _siblings.length == _ceilLog2(_totalLeaves),
                          "Lib_MerkleTree: Total siblings does not correctly correspond to total leaves."
                      );
                      bytes32 computedRoot = _leaf;
                      for (uint256 i = 0; i < _siblings.length; i++) {
                          if ((_index & 1) == 1) {
                              computedRoot = keccak256(
                                  abi.encodePacked(
                                      _siblings[i],
                                      computedRoot
                                  )
                              );
                          } else {
                              computedRoot = keccak256(
                                  abi.encodePacked(
                                      computedRoot,
                                      _siblings[i]
                                  )
                              );
                          }
                          _index >>= 1;
                      }
                      return _root == computedRoot;
                  }
                  /*********************
                   * Private Functions *
                   *********************/
                  /**
                   * Calculates the integer ceiling of the log base 2 of an input.
                   * @param _in Unsigned input to calculate the log.
                   * @return ceil(log_base_2(_in))
                   */
                  function _ceilLog2(
                      uint256 _in
                  )
                      private
                      pure
                      returns (
                          uint256
                      )
                  {
                      require(
                          _in > 0,
                          "Lib_MerkleTree: Cannot compute ceil(log_2) of 0."
                      );
                      if (_in == 1) {
                          return 0;
                      }
                      // Find the highest set bit (will be floor(log_2)).
                      // Borrowed with <3 from https://github.com/ethereum/solidity-examples
                      uint256 val = _in;
                      uint256 highest = 0;
                      for (uint256 i = 128; i >= 1; i >>= 1) {
                          if (val & (uint(1) << i) - 1 << i != 0) {
                              highest += i;
                              val >>= i;
                          }
                      }
                      // Increment by one if this is not a perfect logarithm.
                      if ((uint(1) << highest) != _in) {
                          highest += 1;
                      }
                      return highest;
                  }
              }// 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: MIT
              pragma solidity >=0.6.0 <0.8.0;
              /**
               * @dev Contract module that helps prevent reentrant calls to a function.
               *
               * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
               * available, which can be applied to functions to make sure there are no nested
               * (reentrant) calls to them.
               *
               * Note that because there is a single `nonReentrant` guard, functions marked as
               * `nonReentrant` may not call one another. This can be worked around by making
               * those functions `private`, and then adding `external` `nonReentrant` entry
               * points to them.
               *
               * TIP: If you would like to learn more about reentrancy and alternative ways
               * to protect against it, check out our blog post
               * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
               */
              abstract contract ReentrancyGuard {
                  // Booleans are more expensive than uint256 or any type that takes up a full
                  // word because each write operation emits an extra SLOAD to first read the
                  // slot's contents, replace the bits taken up by the boolean, and then write
                  // back. This is the compiler's defense against contract upgrades and
                  // pointer aliasing, and it cannot be disabled.
                  // The values being non-zero value makes deployment a bit more expensive,
                  // but in exchange the refund on every call to nonReentrant will be lower in
                  // amount. Since refunds are capped to a percentage of the total
                  // transaction's gas, it is best to keep them low in cases like this one, to
                  // increase the likelihood of the full refund coming into effect.
                  uint256 private constant _NOT_ENTERED = 1;
                  uint256 private constant _ENTERED = 2;
                  uint256 private _status;
                  constructor () internal {
                      _status = _NOT_ENTERED;
                  }
                  /**
                   * @dev Prevents a contract from calling itself, directly or indirectly.
                   * Calling a `nonReentrant` function from another `nonReentrant`
                   * function is not supported. It is possible to prevent this from happening
                   * by making the `nonReentrant` function external, and make it call a
                   * `private` function that does the actual work.
                   */
                  modifier nonReentrant() {
                      // On the first call to nonReentrant, _notEntered will be true
                      require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                      // Any calls to nonReentrant after this point will fail
                      _status = _ENTERED;
                      _;
                      // By storing the original value once again, a refund is triggered (see
                      // https://eips.ethereum.org/EIPS/eip-2200)
                      _status = _NOT_ENTERED;
                  }
              }
              

              File 6 of 8: OptimismMessengerWrapper
              // SPDX-License-Identifier: MIT
              pragma solidity 0.6.12;
              pragma experimental ABIEncoderV2;
              import "@openzeppelin/contracts/access/Ownable.sol";
              import "../interfaces/optimism/messengers/iOVM_L1CrossDomainMessenger.sol";
              import "./MessengerWrapper.sol";
              /**
               * @dev A MessengerWrapper for Optimism - https://community.optimism.io/docs/
               * @notice Deployed on layer-1
               */
              contract OptimismMessengerWrapper is MessengerWrapper, Ownable {
                  iOVM_L1CrossDomainMessenger public immutable l1MessengerAddress;
                  address public immutable l2BridgeAddress;
                  uint256 public defaultL2GasLimit;
                  mapping (bytes4 => uint256) public l2GasLimitForSignature;
                  constructor(
                      address _l1BridgeAddress,
                      address _l2BridgeAddress,
                      iOVM_L1CrossDomainMessenger _l1MessengerAddress,
                      uint256 _defaultL2GasLimit
                  )
                      public
                      MessengerWrapper(_l1BridgeAddress)
                  {
                      l2BridgeAddress = _l2BridgeAddress;
                      l1MessengerAddress = _l1MessengerAddress;
                      defaultL2GasLimit = _defaultL2GasLimit;
                  }
                  /** 
                   * @dev Sends a message to the l2BridgeAddress from layer-1
                   * @param _calldata The data that l2BridgeAddress will be called with
                   */
                  function sendCrossDomainMessage(bytes memory _calldata) public override onlyL1Bridge {
                      uint256 l2GasLimit = l2GasLimitForCalldata(_calldata);
                      l1MessengerAddress.sendMessage(
                          l2BridgeAddress,
                          _calldata,
                          uint32(l2GasLimit)
                      );
                  }
                  function verifySender(address l1BridgeCaller, bytes memory /*_data*/) public override {
                      require(l1BridgeCaller == address(l1MessengerAddress), "OVM_MSG_WPR: Caller is not l1MessengerAddress");
                      // Verify that cross-domain sender is l2BridgeAddress
                      require(l1MessengerAddress.xDomainMessageSender() == l2BridgeAddress, "OVM_MSG_WPR: Invalid cross-domain sender");
                  }
                  function setDefaultL2GasLimit(uint256 _l2GasLimit) external onlyOwner {
                      defaultL2GasLimit = _l2GasLimit;
                  }
                  function setL2GasLimitForSignature(uint256 _l2GasLimit, bytes4 signature) external onlyOwner {
                      l2GasLimitForSignature[signature] = _l2GasLimit;
                  }
                  // Private functions
                  function l2GasLimitForCalldata(bytes memory _calldata) private view returns (uint256) {
                      uint256 l2GasLimit;
                      if (_calldata.length >= 4) {
                          bytes4 functionSignature = bytes4(toUint32(_calldata, 0));
                          l2GasLimit = l2GasLimitForSignature[functionSignature];
                      }
                      if (l2GasLimit == 0) {
                          l2GasLimit = defaultL2GasLimit;
                      }
                      return l2GasLimit;
                  }
                  // source: https://github.com/GNSPS/solidity-bytes-utils/blob/master/contracts/BytesLib.sol
                  function toUint32(bytes memory _bytes, uint256 _start) private pure returns (uint32) {
                      require(_bytes.length >= _start + 4, "OVM_MSG_WPR: out of bounds");
                      uint32 tempUint;
                      assembly {
                          tempUint := mload(add(add(_bytes, 0x4), _start))
                      }
                      return tempUint;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              import "../utils/Context.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              abstract contract Ownable is Context {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  constructor () internal {
                      address msgSender = _msgSender();
                      _owner = msgSender;
                      emit OwnershipTransferred(address(0), msgSender);
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view virtual returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(owner() == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      emit OwnershipTransferred(_owner, address(0));
                      _owner = address(0);
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      emit OwnershipTransferred(_owner, newOwner);
                      _owner = newOwner;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.8.0;
              pragma experimental ABIEncoderV2;
              import { iOVM_BaseCrossDomainMessenger } from "./iOVM_BaseCrossDomainMessenger.sol";
              /**
               * @title iOVM_L1CrossDomainMessenger
               */
              interface iOVM_L1CrossDomainMessenger is iOVM_BaseCrossDomainMessenger {}// SPDX-License-Identifier: MIT
              pragma solidity >=0.6.12 <0.8.0;
              pragma experimental ABIEncoderV2;
              import "../interfaces/IMessengerWrapper.sol";
              abstract contract MessengerWrapper is IMessengerWrapper {
                  address public immutable l1BridgeAddress;
                  constructor(address _l1BridgeAddress) internal {
                      l1BridgeAddress = _l1BridgeAddress;
                  }
                  modifier onlyL1Bridge {
                      require(msg.sender == l1BridgeAddress, "MW: Sender must be the L1 Bridge");
                      _;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              /*
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with GSN meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address payable) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes memory) {
                      this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                      return msg.data;
                  }
              }
              // SPDX-License-Identifier: MIT
              // +build ovm
              pragma solidity >0.5.0 <0.8.0;
              pragma experimental ABIEncoderV2;
              /**
               * @title iOVM_BaseCrossDomainMessenger
               */
              interface iOVM_BaseCrossDomainMessenger {
                  /**********
                   * Events *
                   **********/
                  event SentMessage(bytes message);
                  event RelayedMessage(bytes32 msgHash);
                  /**********************
                   * Contract Variables *
                   **********************/
                  function xDomainMessageSender() external view returns (address);
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Sends a cross domain message to the target messenger.
                   * @param _target Target contract address.
                   * @param _message Message to send to the target.
                   * @param _gasLimit Gas limit for the provided message.
                   */
                  function sendMessage(
                      address _target,
                      bytes calldata _message,
                      uint32 _gasLimit
                  ) external;
                  function deposit(
                      address _depositor,
                      uint256 _amount,
                      bool _send
                  ) external;
              }// SPDX-License-Identifier: MIT
              pragma solidity >=0.6.12 <0.8.0;
              pragma experimental ABIEncoderV2;
              interface IMessengerWrapper {
                  function sendCrossDomainMessage(bytes memory _calldata) external;
                  function verifySender(address l1BridgeCaller, bytes memory _data) external;
              }
              

              File 7 of 8: Lib_AddressManager
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              import "../utils/Context.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              abstract contract Ownable is Context {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  constructor () internal {
                      address msgSender = _msgSender();
                      _owner = msgSender;
                      emit OwnershipTransferred(address(0), msgSender);
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view virtual returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(owner() == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      emit OwnershipTransferred(_owner, address(0));
                      _owner = address(0);
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      emit OwnershipTransferred(_owner, newOwner);
                      _owner = newOwner;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              /*
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with GSN meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address payable) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes memory) {
                      this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                      return msg.data;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.8.0;
              /* External Imports */
              import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
              /**
               * @title Lib_AddressManager
               */
              contract Lib_AddressManager is Ownable {
                  /**********
                   * Events *
                   **********/
                  event AddressSet(
                      string indexed _name,
                      address _newAddress,
                      address _oldAddress
                  );
                  /*************
                   * Variables *
                   *************/
                  mapping (bytes32 => address) private addresses;
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Changes the address associated with a particular name.
                   * @param _name String name to associate an address with.
                   * @param _address Address to associate with the name.
                   */
                  function setAddress(
                      string memory _name,
                      address _address
                  )
                      external
                      onlyOwner
                  {
                      bytes32 nameHash = _getNameHash(_name);
                      address oldAddress = addresses[nameHash];
                      addresses[nameHash] = _address;
                      emit AddressSet(
                          _name,
                          _address,
                          oldAddress
                      );
                  }
                  /**
                   * Retrieves the address associated with a given name.
                   * @param _name Name to retrieve an address for.
                   * @return Address associated with the given name.
                   */
                  function getAddress(
                      string memory _name
                  )
                      external
                      view
                      returns (
                          address
                      )
                  {
                      return addresses[_getNameHash(_name)];
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Computes the hash of a name.
                   * @param _name Name to compute a hash for.
                   * @return Hash of the given name.
                   */
                  function _getNameHash(
                      string memory _name
                  )
                      internal
                      pure
                      returns (
                          bytes32
                      )
                  {
                      return keccak256(abi.encodePacked(_name));
                  }
              }
              

              File 8 of 8: L1CrossDomainMessenger
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "../utils/ContextUpgradeable.sol";
              import "../proxy/utils/Initializable.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  function __Ownable_init() internal initializer {
                      __Context_init_unchained();
                      __Ownable_init_unchained();
                  }
                  function __Ownable_init_unchained() internal initializer {
                      _setOwner(_msgSender());
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view virtual returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(owner() == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      _setOwner(address(0));
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      _setOwner(newOwner);
                  }
                  function _setOwner(address newOwner) private {
                      address oldOwner = _owner;
                      _owner = newOwner;
                      emit OwnershipTransferred(oldOwner, newOwner);
                  }
                  uint256[49] private __gap;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              /**
               * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
               * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
               * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
               * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
               *
               * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
               * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
               *
               * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
               * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
               */
              abstract contract Initializable {
                  /**
                   * @dev Indicates that the contract has been initialized.
                   */
                  bool private _initialized;
                  /**
                   * @dev Indicates that the contract is in the process of being initialized.
                   */
                  bool private _initializing;
                  /**
                   * @dev Modifier to protect an initializer function from being invoked twice.
                   */
                  modifier initializer() {
                      require(_initializing || !_initialized, "Initializable: contract is already initialized");
                      bool isTopLevelCall = !_initializing;
                      if (isTopLevelCall) {
                          _initializing = true;
                          _initialized = true;
                      }
                      _;
                      if (isTopLevelCall) {
                          _initializing = false;
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "../utils/ContextUpgradeable.sol";
              import "../proxy/utils/Initializable.sol";
              /**
               * @dev Contract module which allows children to implement an emergency stop
               * mechanism that can be triggered by an authorized account.
               *
               * This module is used through inheritance. It will make available the
               * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
               * the functions of your contract. Note that they will not be pausable by
               * simply including this module, only once the modifiers are put in place.
               */
              abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
                  /**
                   * @dev Emitted when the pause is triggered by `account`.
                   */
                  event Paused(address account);
                  /**
                   * @dev Emitted when the pause is lifted by `account`.
                   */
                  event Unpaused(address account);
                  bool private _paused;
                  /**
                   * @dev Initializes the contract in unpaused state.
                   */
                  function __Pausable_init() internal initializer {
                      __Context_init_unchained();
                      __Pausable_init_unchained();
                  }
                  function __Pausable_init_unchained() internal initializer {
                      _paused = false;
                  }
                  /**
                   * @dev Returns true if the contract is paused, and false otherwise.
                   */
                  function paused() public view virtual returns (bool) {
                      return _paused;
                  }
                  /**
                   * @dev Modifier to make a function callable only when the contract is not paused.
                   *
                   * Requirements:
                   *
                   * - The contract must not be paused.
                   */
                  modifier whenNotPaused() {
                      require(!paused(), "Pausable: paused");
                      _;
                  }
                  /**
                   * @dev Modifier to make a function callable only when the contract is paused.
                   *
                   * Requirements:
                   *
                   * - The contract must be paused.
                   */
                  modifier whenPaused() {
                      require(paused(), "Pausable: not paused");
                      _;
                  }
                  /**
                   * @dev Triggers stopped state.
                   *
                   * Requirements:
                   *
                   * - The contract must not be paused.
                   */
                  function _pause() internal virtual whenNotPaused {
                      _paused = true;
                      emit Paused(_msgSender());
                  }
                  /**
                   * @dev Returns to normal state.
                   *
                   * Requirements:
                   *
                   * - The contract must be paused.
                   */
                  function _unpause() internal virtual whenPaused {
                      _paused = false;
                      emit Unpaused(_msgSender());
                  }
                  uint256[49] private __gap;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "../proxy/utils/Initializable.sol";
              /**
               * @dev Contract module that helps prevent reentrant calls to a function.
               *
               * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
               * available, which can be applied to functions to make sure there are no nested
               * (reentrant) calls to them.
               *
               * Note that because there is a single `nonReentrant` guard, functions marked as
               * `nonReentrant` may not call one another. This can be worked around by making
               * those functions `private`, and then adding `external` `nonReentrant` entry
               * points to them.
               *
               * TIP: If you would like to learn more about reentrancy and alternative ways
               * to protect against it, check out our blog post
               * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
               */
              abstract contract ReentrancyGuardUpgradeable is Initializable {
                  // Booleans are more expensive than uint256 or any type that takes up a full
                  // word because each write operation emits an extra SLOAD to first read the
                  // slot's contents, replace the bits taken up by the boolean, and then write
                  // back. This is the compiler's defense against contract upgrades and
                  // pointer aliasing, and it cannot be disabled.
                  // The values being non-zero value makes deployment a bit more expensive,
                  // but in exchange the refund on every call to nonReentrant will be lower in
                  // amount. Since refunds are capped to a percentage of the total
                  // transaction's gas, it is best to keep them low in cases like this one, to
                  // increase the likelihood of the full refund coming into effect.
                  uint256 private constant _NOT_ENTERED = 1;
                  uint256 private constant _ENTERED = 2;
                  uint256 private _status;
                  function __ReentrancyGuard_init() internal initializer {
                      __ReentrancyGuard_init_unchained();
                  }
                  function __ReentrancyGuard_init_unchained() internal initializer {
                      _status = _NOT_ENTERED;
                  }
                  /**
                   * @dev Prevents a contract from calling itself, directly or indirectly.
                   * Calling a `nonReentrant` function from another `nonReentrant`
                   * function is not supported. It is possible to prevent this from happening
                   * by making the `nonReentrant` function external, and make it call a
                   * `private` function that does the actual work.
                   */
                  modifier nonReentrant() {
                      // On the first call to nonReentrant, _notEntered will be true
                      require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                      // Any calls to nonReentrant after this point will fail
                      _status = _ENTERED;
                      _;
                      // By storing the original value once again, a refund is triggered (see
                      // https://eips.ethereum.org/EIPS/eip-2200)
                      _status = _NOT_ENTERED;
                  }
                  uint256[49] private __gap;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "../proxy/utils/Initializable.sol";
              /**
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract ContextUpgradeable is Initializable {
                  function __Context_init() internal initializer {
                      __Context_init_unchained();
                  }
                  function __Context_init_unchained() internal initializer {
                  }
                  function _msgSender() internal view virtual returns (address) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes calldata) {
                      return msg.data;
                  }
                  uint256[50] private __gap;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "../utils/Context.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              abstract contract Ownable is Context {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  constructor() {
                      _setOwner(_msgSender());
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view virtual returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(owner() == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      _setOwner(address(0));
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      _setOwner(newOwner);
                  }
                  function _setOwner(address newOwner) private {
                      address oldOwner = _owner;
                      _owner = newOwner;
                      emit OwnershipTransferred(oldOwner, newOwner);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              /**
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes calldata) {
                      return msg.data;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
              /* Interface Imports */
              import { ICrossDomainMessenger } from "../../libraries/bridge/ICrossDomainMessenger.sol";
              /**
               * @title IL1CrossDomainMessenger
               */
              interface IL1CrossDomainMessenger is ICrossDomainMessenger {
                  /*******************
                   * Data Structures *
                   *******************/
                  struct L2MessageInclusionProof {
                      bytes32 stateRoot;
                      Lib_OVMCodec.ChainBatchHeader stateRootBatchHeader;
                      Lib_OVMCodec.ChainInclusionProof stateRootProof;
                      bytes stateTrieWitness;
                      bytes storageTrieWitness;
                  }
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Relays a cross domain message to a contract.
                   * @param _target Target contract address.
                   * @param _sender Message sender address.
                   * @param _message Message to send to the target.
                   * @param _messageNonce Nonce for the provided message.
                   * @param _proof Inclusion proof for the given message.
                   */
                  function relayMessage(
                      address _target,
                      address _sender,
                      bytes memory _message,
                      uint256 _messageNonce,
                      L2MessageInclusionProof memory _proof
                  ) external;
                  /**
                   * Replays a cross domain message to the target messenger.
                   * @param _target Target contract address.
                   * @param _sender Original sender address.
                   * @param _message Message to send to the target.
                   * @param _queueIndex CTC Queue index for the message to replay.
                   * @param _oldGasLimit Original gas limit used to send the message.
                   * @param _newGasLimit New gas limit to be used for this message.
                   */
                  function replayMessage(
                      address _target,
                      address _sender,
                      bytes memory _message,
                      uint256 _queueIndex,
                      uint32 _oldGasLimit,
                      uint32 _newGasLimit
                  ) external;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { AddressAliasHelper } from "../../standards/AddressAliasHelper.sol";
              import { Lib_AddressResolver } from "../../libraries/resolver/Lib_AddressResolver.sol";
              import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
              import { Lib_AddressManager } from "../../libraries/resolver/Lib_AddressManager.sol";
              import { Lib_SecureMerkleTrie } from "../../libraries/trie/Lib_SecureMerkleTrie.sol";
              import { Lib_DefaultValues } from "../../libraries/constants/Lib_DefaultValues.sol";
              import { Lib_PredeployAddresses } from "../../libraries/constants/Lib_PredeployAddresses.sol";
              import { Lib_CrossDomainUtils } from "../../libraries/bridge/Lib_CrossDomainUtils.sol";
              /* Interface Imports */
              import { IL1CrossDomainMessenger } from "./IL1CrossDomainMessenger.sol";
              import { ICanonicalTransactionChain } from "../rollup/ICanonicalTransactionChain.sol";
              import { IStateCommitmentChain } from "../rollup/IStateCommitmentChain.sol";
              /* External Imports */
              import {
                  OwnableUpgradeable
              } from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
              import {
                  PausableUpgradeable
              } from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
              import {
                  ReentrancyGuardUpgradeable
              } from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
              /**
               * @title L1CrossDomainMessenger
               * @dev The L1 Cross Domain Messenger contract sends messages from L1 to L2, and relays messages
               * from L2 onto L1. In the event that a message sent from L1 to L2 is rejected for exceeding the L2
               * epoch gas limit, it can be resubmitted via this contract's replay function.
               *
               * Runtime target: EVM
               */
              contract L1CrossDomainMessenger is
                  IL1CrossDomainMessenger,
                  Lib_AddressResolver,
                  OwnableUpgradeable,
                  PausableUpgradeable,
                  ReentrancyGuardUpgradeable
              {
                  /**********
                   * Events *
                   **********/
                  event MessageBlocked(bytes32 indexed _xDomainCalldataHash);
                  event MessageAllowed(bytes32 indexed _xDomainCalldataHash);
                  /**********************
                   * Contract Variables *
                   **********************/
                  mapping(bytes32 => bool) public blockedMessages;
                  mapping(bytes32 => bool) public relayedMessages;
                  mapping(bytes32 => bool) public successfulMessages;
                  address internal xDomainMsgSender = Lib_DefaultValues.DEFAULT_XDOMAIN_SENDER;
                  /***************
                   * Constructor *
                   ***************/
                  /**
                   * This contract is intended to be behind a delegate proxy.
                   * We pass the zero address to the address resolver just to satisfy the constructor.
                   * We still need to set this value in initialize().
                   */
                  constructor() Lib_AddressResolver(address(0)) {}
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * @param _libAddressManager Address of the Address Manager.
                   */
                  function initialize(address _libAddressManager) public initializer {
                      require(
                          address(libAddressManager) == address(0),
                          "L1CrossDomainMessenger already intialized."
                      );
                      libAddressManager = Lib_AddressManager(_libAddressManager);
                      xDomainMsgSender = Lib_DefaultValues.DEFAULT_XDOMAIN_SENDER;
                      // Initialize upgradable OZ contracts
                      __Context_init_unchained(); // Context is a dependency for both Ownable and Pausable
                      __Ownable_init_unchained();
                      __Pausable_init_unchained();
                      __ReentrancyGuard_init_unchained();
                  }
                  /**
                   * Pause relaying.
                   */
                  function pause() external onlyOwner {
                      _pause();
                  }
                  /**
                   * Block a message.
                   * @param _xDomainCalldataHash Hash of the message to block.
                   */
                  function blockMessage(bytes32 _xDomainCalldataHash) external onlyOwner {
                      blockedMessages[_xDomainCalldataHash] = true;
                      emit MessageBlocked(_xDomainCalldataHash);
                  }
                  /**
                   * Allow a message.
                   * @param _xDomainCalldataHash Hash of the message to block.
                   */
                  function allowMessage(bytes32 _xDomainCalldataHash) external onlyOwner {
                      blockedMessages[_xDomainCalldataHash] = false;
                      emit MessageAllowed(_xDomainCalldataHash);
                  }
                  function xDomainMessageSender() public view returns (address) {
                      require(
                          xDomainMsgSender != Lib_DefaultValues.DEFAULT_XDOMAIN_SENDER,
                          "xDomainMessageSender is not set"
                      );
                      return xDomainMsgSender;
                  }
                  /**
                   * Sends a cross domain message to the target messenger.
                   * @param _target Target contract address.
                   * @param _message Message to send to the target.
                   * @param _gasLimit Gas limit for the provided message.
                   */
                  function sendMessage(
                      address _target,
                      bytes memory _message,
                      uint32 _gasLimit
                  ) public {
                      address ovmCanonicalTransactionChain = resolve("CanonicalTransactionChain");
                      // Use the CTC queue length as nonce
                      uint40 nonce = ICanonicalTransactionChain(ovmCanonicalTransactionChain).getQueueLength();
                      bytes memory xDomainCalldata = Lib_CrossDomainUtils.encodeXDomainCalldata(
                          _target,
                          msg.sender,
                          _message,
                          nonce
                      );
                      _sendXDomainMessage(ovmCanonicalTransactionChain, xDomainCalldata, _gasLimit);
                      emit SentMessage(_target, msg.sender, _message, nonce, _gasLimit);
                  }
                  /**
                   * Relays a cross domain message to a contract.
                   * @inheritdoc IL1CrossDomainMessenger
                   */
                  function relayMessage(
                      address _target,
                      address _sender,
                      bytes memory _message,
                      uint256 _messageNonce,
                      L2MessageInclusionProof memory _proof
                  ) public nonReentrant whenNotPaused {
                      bytes memory xDomainCalldata = Lib_CrossDomainUtils.encodeXDomainCalldata(
                          _target,
                          _sender,
                          _message,
                          _messageNonce
                      );
                      require(
                          _verifyXDomainMessage(xDomainCalldata, _proof) == true,
                          "Provided message could not be verified."
                      );
                      bytes32 xDomainCalldataHash = keccak256(xDomainCalldata);
                      require(
                          successfulMessages[xDomainCalldataHash] == false,
                          "Provided message has already been received."
                      );
                      require(
                          blockedMessages[xDomainCalldataHash] == false,
                          "Provided message has been blocked."
                      );
                      require(
                          _target != resolve("CanonicalTransactionChain"),
                          "Cannot send L2->L1 messages to L1 system contracts."
                      );
                      xDomainMsgSender = _sender;
                      (bool success, ) = _target.call(_message);
                      xDomainMsgSender = Lib_DefaultValues.DEFAULT_XDOMAIN_SENDER;
                      // Mark the message as received if the call was successful. Ensures that a message can be
                      // relayed multiple times in the case that the call reverted.
                      if (success == true) {
                          successfulMessages[xDomainCalldataHash] = true;
                          emit RelayedMessage(xDomainCalldataHash);
                      } else {
                          emit FailedRelayedMessage(xDomainCalldataHash);
                      }
                      // Store an identifier that can be used to prove that the given message was relayed by some
                      // user. Gives us an easy way to pay relayers for their work.
                      bytes32 relayId = keccak256(abi.encodePacked(xDomainCalldata, msg.sender, block.number));
                      relayedMessages[relayId] = true;
                  }
                  /**
                   * Replays a cross domain message to the target messenger.
                   * @inheritdoc IL1CrossDomainMessenger
                   */
                  function replayMessage(
                      address _target,
                      address _sender,
                      bytes memory _message,
                      uint256 _queueIndex,
                      uint32 _oldGasLimit,
                      uint32 _newGasLimit
                  ) public {
                      // Verify that the message is in the queue:
                      address canonicalTransactionChain = resolve("CanonicalTransactionChain");
                      Lib_OVMCodec.QueueElement memory element = ICanonicalTransactionChain(
                          canonicalTransactionChain
                      ).getQueueElement(_queueIndex);
                      // Compute the calldata that was originally used to send the message.
                      bytes memory xDomainCalldata = Lib_CrossDomainUtils.encodeXDomainCalldata(
                          _target,
                          _sender,
                          _message,
                          _queueIndex
                      );
                      // Compute the transactionHash
                      bytes32 transactionHash = keccak256(
                          abi.encode(
                              AddressAliasHelper.applyL1ToL2Alias(address(this)),
                              Lib_PredeployAddresses.L2_CROSS_DOMAIN_MESSENGER,
                              _oldGasLimit,
                              xDomainCalldata
                          )
                      );
                      // Now check that the provided message data matches the one in the queue element.
                      require(
                          transactionHash == element.transactionHash,
                          "Provided message has not been enqueued."
                      );
                      // Send the same message but with the new gas limit.
                      _sendXDomainMessage(canonicalTransactionChain, xDomainCalldata, _newGasLimit);
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Verifies that the given message is valid.
                   * @param _xDomainCalldata Calldata to verify.
                   * @param _proof Inclusion proof for the message.
                   * @return Whether or not the provided message is valid.
                   */
                  function _verifyXDomainMessage(
                      bytes memory _xDomainCalldata,
                      L2MessageInclusionProof memory _proof
                  ) internal view returns (bool) {
                      return (_verifyStateRootProof(_proof) && _verifyStorageProof(_xDomainCalldata, _proof));
                  }
                  /**
                   * Verifies that the state root within an inclusion proof is valid.
                   * @param _proof Message inclusion proof.
                   * @return Whether or not the provided proof is valid.
                   */
                  function _verifyStateRootProof(L2MessageInclusionProof memory _proof)
                      internal
                      view
                      returns (bool)
                  {
                      IStateCommitmentChain ovmStateCommitmentChain = IStateCommitmentChain(
                          resolve("StateCommitmentChain")
                      );
                      return (ovmStateCommitmentChain.insideFraudProofWindow(_proof.stateRootBatchHeader) ==
                          false &&
                          ovmStateCommitmentChain.verifyStateCommitment(
                              _proof.stateRoot,
                              _proof.stateRootBatchHeader,
                              _proof.stateRootProof
                          ));
                  }
                  /**
                   * Verifies that the storage proof within an inclusion proof is valid.
                   * @param _xDomainCalldata Encoded message calldata.
                   * @param _proof Message inclusion proof.
                   * @return Whether or not the provided proof is valid.
                   */
                  function _verifyStorageProof(
                      bytes memory _xDomainCalldata,
                      L2MessageInclusionProof memory _proof
                  ) internal view returns (bool) {
                      bytes32 storageKey = keccak256(
                          abi.encodePacked(
                              keccak256(
                                  abi.encodePacked(
                                      _xDomainCalldata,
                                      Lib_PredeployAddresses.L2_CROSS_DOMAIN_MESSENGER
                                  )
                              ),
                              uint256(0)
                          )
                      );
                      (bool exists, bytes memory encodedMessagePassingAccount) = Lib_SecureMerkleTrie.get(
                          abi.encodePacked(Lib_PredeployAddresses.L2_TO_L1_MESSAGE_PASSER),
                          _proof.stateTrieWitness,
                          _proof.stateRoot
                      );
                      require(
                          exists == true,
                          "Message passing predeploy has not been initialized or invalid proof provided."
                      );
                      Lib_OVMCodec.EVMAccount memory account = Lib_OVMCodec.decodeEVMAccount(
                          encodedMessagePassingAccount
                      );
                      return
                          Lib_SecureMerkleTrie.verifyInclusionProof(
                              abi.encodePacked(storageKey),
                              abi.encodePacked(uint8(1)),
                              _proof.storageTrieWitness,
                              account.storageRoot
                          );
                  }
                  /**
                   * Sends a cross domain message.
                   * @param _canonicalTransactionChain Address of the CanonicalTransactionChain instance.
                   * @param _message Message to send.
                   * @param _gasLimit OVM gas limit for the message.
                   */
                  function _sendXDomainMessage(
                      address _canonicalTransactionChain,
                      bytes memory _message,
                      uint256 _gasLimit
                  ) internal {
                      ICanonicalTransactionChain(_canonicalTransactionChain).enqueue(
                          Lib_PredeployAddresses.L2_CROSS_DOMAIN_MESSENGER,
                          _gasLimit,
                          _message
                      );
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.9.0;
              /* Library Imports */
              import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
              /* Interface Imports */
              import { IChainStorageContainer } from "./IChainStorageContainer.sol";
              /**
               * @title ICanonicalTransactionChain
               */
              interface ICanonicalTransactionChain {
                  /**********
                   * Events *
                   **********/
                  event L2GasParamsUpdated(
                      uint256 l2GasDiscountDivisor,
                      uint256 enqueueGasCost,
                      uint256 enqueueL2GasPrepaid
                  );
                  event TransactionEnqueued(
                      address indexed _l1TxOrigin,
                      address indexed _target,
                      uint256 _gasLimit,
                      bytes _data,
                      uint256 indexed _queueIndex,
                      uint256 _timestamp
                  );
                  event QueueBatchAppended(
                      uint256 _startingQueueIndex,
                      uint256 _numQueueElements,
                      uint256 _totalElements
                  );
                  event SequencerBatchAppended(
                      uint256 _startingQueueIndex,
                      uint256 _numQueueElements,
                      uint256 _totalElements
                  );
                  event TransactionBatchAppended(
                      uint256 indexed _batchIndex,
                      bytes32 _batchRoot,
                      uint256 _batchSize,
                      uint256 _prevTotalElements,
                      bytes _extraData
                  );
                  /***********
                   * Structs *
                   ***********/
                  struct BatchContext {
                      uint256 numSequencedTransactions;
                      uint256 numSubsequentQueueTransactions;
                      uint256 timestamp;
                      uint256 blockNumber;
                  }
                  /*******************************
                   * Authorized Setter Functions *
                   *******************************/
                  /**
                   * Allows the Burn Admin to update the parameters which determine the amount of gas to burn.
                   * The value of enqueueL2GasPrepaid is immediately updated as well.
                   */
                  function setGasParams(uint256 _l2GasDiscountDivisor, uint256 _enqueueGasCost) external;
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Accesses the batch storage container.
                   * @return Reference to the batch storage container.
                   */
                  function batches() external view returns (IChainStorageContainer);
                  /**
                   * Retrieves the total number of elements submitted.
                   * @return _totalElements Total submitted elements.
                   */
                  function getTotalElements() external view returns (uint256 _totalElements);
                  /**
                   * Retrieves the total number of batches submitted.
                   * @return _totalBatches Total submitted batches.
                   */
                  function getTotalBatches() external view returns (uint256 _totalBatches);
                  /**
                   * Returns the index of the next element to be enqueued.
                   * @return Index for the next queue element.
                   */
                  function getNextQueueIndex() external view returns (uint40);
                  /**
                   * Gets the queue element at a particular index.
                   * @param _index Index of the queue element to access.
                   * @return _element Queue element at the given index.
                   */
                  function getQueueElement(uint256 _index)
                      external
                      view
                      returns (Lib_OVMCodec.QueueElement memory _element);
                  /**
                   * Returns the timestamp of the last transaction.
                   * @return Timestamp for the last transaction.
                   */
                  function getLastTimestamp() external view returns (uint40);
                  /**
                   * Returns the blocknumber of the last transaction.
                   * @return Blocknumber for the last transaction.
                   */
                  function getLastBlockNumber() external view returns (uint40);
                  /**
                   * Get the number of queue elements which have not yet been included.
                   * @return Number of pending queue elements.
                   */
                  function getNumPendingQueueElements() external view returns (uint40);
                  /**
                   * Retrieves the length of the queue, including
                   * both pending and canonical transactions.
                   * @return Length of the queue.
                   */
                  function getQueueLength() external view returns (uint40);
                  /**
                   * Adds a transaction to the queue.
                   * @param _target Target contract to send the transaction to.
                   * @param _gasLimit Gas limit for the given transaction.
                   * @param _data Transaction data.
                   */
                  function enqueue(
                      address _target,
                      uint256 _gasLimit,
                      bytes memory _data
                  ) external;
                  /**
                   * Allows the sequencer to append a batch of transactions.
                   * @dev This function uses a custom encoding scheme for efficiency reasons.
                   * .param _shouldStartAtElement Specific batch we expect to start appending to.
                   * .param _totalElementsToAppend Total number of batch elements we expect to append.
                   * .param _contexts Array of batch contexts.
                   * .param _transactionDataFields Array of raw transaction data.
                   */
                  function appendSequencerBatch(
                      // uint40 _shouldStartAtElement,
                      // uint24 _totalElementsToAppend,
                      // BatchContext[] _contexts,
                      // bytes[] _transactionDataFields
                  ) external;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.9.0;
              /**
               * @title IChainStorageContainer
               */
              interface IChainStorageContainer {
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Sets the container's global metadata field. We're using `bytes27` here because we use five
                   * bytes to maintain the length of the underlying data structure, meaning we have an extra
                   * 27 bytes to store arbitrary data.
                   * @param _globalMetadata New global metadata to set.
                   */
                  function setGlobalMetadata(bytes27 _globalMetadata) external;
                  /**
                   * Retrieves the container's global metadata field.
                   * @return Container global metadata field.
                   */
                  function getGlobalMetadata() external view returns (bytes27);
                  /**
                   * Retrieves the number of objects stored in the container.
                   * @return Number of objects in the container.
                   */
                  function length() external view returns (uint256);
                  /**
                   * Pushes an object into the container.
                   * @param _object A 32 byte value to insert into the container.
                   */
                  function push(bytes32 _object) external;
                  /**
                   * Pushes an object into the container. Function allows setting the global metadata since
                   * we'll need to touch the "length" storage slot anyway, which also contains the global
                   * metadata (it's an optimization).
                   * @param _object A 32 byte value to insert into the container.
                   * @param _globalMetadata New global metadata for the container.
                   */
                  function push(bytes32 _object, bytes27 _globalMetadata) external;
                  /**
                   * Retrieves an object from the container.
                   * @param _index Index of the particular object to access.
                   * @return 32 byte object value.
                   */
                  function get(uint256 _index) external view returns (bytes32);
                  /**
                   * Removes all objects after and including a given index.
                   * @param _index Object index to delete from.
                   */
                  function deleteElementsAfterInclusive(uint256 _index) external;
                  /**
                   * Removes all objects after and including a given index. Also allows setting the global
                   * metadata field.
                   * @param _index Object index to delete from.
                   * @param _globalMetadata New global metadata for the container.
                   */
                  function deleteElementsAfterInclusive(uint256 _index, bytes27 _globalMetadata) external;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.9.0;
              /* Library Imports */
              import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
              /**
               * @title IStateCommitmentChain
               */
              interface IStateCommitmentChain {
                  /**********
                   * Events *
                   **********/
                  event StateBatchAppended(
                      uint256 indexed _batchIndex,
                      bytes32 _batchRoot,
                      uint256 _batchSize,
                      uint256 _prevTotalElements,
                      bytes _extraData
                  );
                  event StateBatchDeleted(uint256 indexed _batchIndex, bytes32 _batchRoot);
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Retrieves the total number of elements submitted.
                   * @return _totalElements Total submitted elements.
                   */
                  function getTotalElements() external view returns (uint256 _totalElements);
                  /**
                   * Retrieves the total number of batches submitted.
                   * @return _totalBatches Total submitted batches.
                   */
                  function getTotalBatches() external view returns (uint256 _totalBatches);
                  /**
                   * Retrieves the timestamp of the last batch submitted by the sequencer.
                   * @return _lastSequencerTimestamp Last sequencer batch timestamp.
                   */
                  function getLastSequencerTimestamp() external view returns (uint256 _lastSequencerTimestamp);
                  /**
                   * Appends a batch of state roots to the chain.
                   * @param _batch Batch of state roots.
                   * @param _shouldStartAtElement Index of the element at which this batch should start.
                   */
                  function appendStateBatch(bytes32[] calldata _batch, uint256 _shouldStartAtElement) external;
                  /**
                   * Deletes all state roots after (and including) a given batch.
                   * @param _batchHeader Header of the batch to start deleting from.
                   */
                  function deleteStateBatch(Lib_OVMCodec.ChainBatchHeader memory _batchHeader) external;
                  /**
                   * Verifies a batch inclusion proof.
                   * @param _element Hash of the element to verify a proof for.
                   * @param _batchHeader Header of the batch in which the element was included.
                   * @param _proof Merkle inclusion proof for the element.
                   */
                  function verifyStateCommitment(
                      bytes32 _element,
                      Lib_OVMCodec.ChainBatchHeader memory _batchHeader,
                      Lib_OVMCodec.ChainInclusionProof memory _proof
                  ) external view returns (bool _verified);
                  /**
                   * Checks whether a given batch is still inside its fraud proof window.
                   * @param _batchHeader Header of the batch to check.
                   * @return _inside Whether or not the batch is inside the fraud proof window.
                   */
                  function insideFraudProofWindow(Lib_OVMCodec.ChainBatchHeader memory _batchHeader)
                      external
                      view
                      returns (bool _inside);
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >0.5.0 <0.9.0;
              /**
               * @title ICrossDomainMessenger
               */
              interface ICrossDomainMessenger {
                  /**********
                   * Events *
                   **********/
                  event SentMessage(
                      address indexed target,
                      address sender,
                      bytes message,
                      uint256 messageNonce,
                      uint256 gasLimit
                  );
                  event RelayedMessage(bytes32 indexed msgHash);
                  event FailedRelayedMessage(bytes32 indexed msgHash);
                  /*************
                   * Variables *
                   *************/
                  function xDomainMessageSender() external view returns (address);
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Sends a cross domain message to the target messenger.
                   * @param _target Target contract address.
                   * @param _message Message to send to the target.
                   * @param _gasLimit Gas limit for the provided message.
                   */
                  function sendMessage(
                      address _target,
                      bytes calldata _message,
                      uint32 _gasLimit
                  ) external;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { Lib_RLPReader } from "../rlp/Lib_RLPReader.sol";
              /**
               * @title Lib_CrossDomainUtils
               */
              library Lib_CrossDomainUtils {
                  /**
                   * Generates the correct cross domain calldata for a message.
                   * @param _target Target contract address.
                   * @param _sender Message sender address.
                   * @param _message Message to send to the target.
                   * @param _messageNonce Nonce for the provided message.
                   * @return ABI encoded cross domain calldata.
                   */
                  function encodeXDomainCalldata(
                      address _target,
                      address _sender,
                      bytes memory _message,
                      uint256 _messageNonce
                  ) internal pure returns (bytes memory) {
                      return
                          abi.encodeWithSignature(
                              "relayMessage(address,address,bytes,uint256)",
                              _target,
                              _sender,
                              _message,
                              _messageNonce
                          );
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { Lib_RLPReader } from "../rlp/Lib_RLPReader.sol";
              import { Lib_RLPWriter } from "../rlp/Lib_RLPWriter.sol";
              import { Lib_BytesUtils } from "../utils/Lib_BytesUtils.sol";
              import { Lib_Bytes32Utils } from "../utils/Lib_Bytes32Utils.sol";
              /**
               * @title Lib_OVMCodec
               */
              library Lib_OVMCodec {
                  /*********
                   * Enums *
                   *********/
                  enum QueueOrigin {
                      SEQUENCER_QUEUE,
                      L1TOL2_QUEUE
                  }
                  /***********
                   * Structs *
                   ***********/
                  struct EVMAccount {
                      uint256 nonce;
                      uint256 balance;
                      bytes32 storageRoot;
                      bytes32 codeHash;
                  }
                  struct ChainBatchHeader {
                      uint256 batchIndex;
                      bytes32 batchRoot;
                      uint256 batchSize;
                      uint256 prevTotalElements;
                      bytes extraData;
                  }
                  struct ChainInclusionProof {
                      uint256 index;
                      bytes32[] siblings;
                  }
                  struct Transaction {
                      uint256 timestamp;
                      uint256 blockNumber;
                      QueueOrigin l1QueueOrigin;
                      address l1TxOrigin;
                      address entrypoint;
                      uint256 gasLimit;
                      bytes data;
                  }
                  struct TransactionChainElement {
                      bool isSequenced;
                      uint256 queueIndex; // QUEUED TX ONLY
                      uint256 timestamp; // SEQUENCER TX ONLY
                      uint256 blockNumber; // SEQUENCER TX ONLY
                      bytes txData; // SEQUENCER TX ONLY
                  }
                  struct QueueElement {
                      bytes32 transactionHash;
                      uint40 timestamp;
                      uint40 blockNumber;
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Encodes a standard OVM transaction.
                   * @param _transaction OVM transaction to encode.
                   * @return Encoded transaction bytes.
                   */
                  function encodeTransaction(Transaction memory _transaction)
                      internal
                      pure
                      returns (bytes memory)
                  {
                      return
                          abi.encodePacked(
                              _transaction.timestamp,
                              _transaction.blockNumber,
                              _transaction.l1QueueOrigin,
                              _transaction.l1TxOrigin,
                              _transaction.entrypoint,
                              _transaction.gasLimit,
                              _transaction.data
                          );
                  }
                  /**
                   * Hashes a standard OVM transaction.
                   * @param _transaction OVM transaction to encode.
                   * @return Hashed transaction
                   */
                  function hashTransaction(Transaction memory _transaction) internal pure returns (bytes32) {
                      return keccak256(encodeTransaction(_transaction));
                  }
                  /**
                   * @notice Decodes an RLP-encoded account state into a useful struct.
                   * @param _encoded RLP-encoded account state.
                   * @return Account state struct.
                   */
                  function decodeEVMAccount(bytes memory _encoded) internal pure returns (EVMAccount memory) {
                      Lib_RLPReader.RLPItem[] memory accountState = Lib_RLPReader.readList(_encoded);
                      return
                          EVMAccount({
                              nonce: Lib_RLPReader.readUint256(accountState[0]),
                              balance: Lib_RLPReader.readUint256(accountState[1]),
                              storageRoot: Lib_RLPReader.readBytes32(accountState[2]),
                              codeHash: Lib_RLPReader.readBytes32(accountState[3])
                          });
                  }
                  /**
                   * Calculates a hash for a given batch header.
                   * @param _batchHeader Header to hash.
                   * @return Hash of the header.
                   */
                  function hashBatchHeader(Lib_OVMCodec.ChainBatchHeader memory _batchHeader)
                      internal
                      pure
                      returns (bytes32)
                  {
                      return
                          keccak256(
                              abi.encode(
                                  _batchHeader.batchRoot,
                                  _batchHeader.batchSize,
                                  _batchHeader.prevTotalElements,
                                  _batchHeader.extraData
                              )
                          );
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_DefaultValues
               */
              library Lib_DefaultValues {
                  // The default x-domain message sender being set to a non-zero value makes
                  // deployment a bit more expensive, but in exchange the refund on every call to
                  // `relayMessage` by the L1 and L2 messengers will be higher.
                  address internal constant DEFAULT_XDOMAIN_SENDER = 0x000000000000000000000000000000000000dEaD;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_PredeployAddresses
               */
              library Lib_PredeployAddresses {
                  address internal constant L2_TO_L1_MESSAGE_PASSER = 0x4200000000000000000000000000000000000000;
                  address internal constant L1_MESSAGE_SENDER = 0x4200000000000000000000000000000000000001;
                  address internal constant DEPLOYER_WHITELIST = 0x4200000000000000000000000000000000000002;
                  address payable internal constant OVM_ETH = payable(0xDeadDeAddeAddEAddeadDEaDDEAdDeaDDeAD0000);
                  address internal constant L2_CROSS_DOMAIN_MESSENGER =
                      0x4200000000000000000000000000000000000007;
                  address internal constant LIB_ADDRESS_MANAGER = 0x4200000000000000000000000000000000000008;
                  address internal constant PROXY_EOA = 0x4200000000000000000000000000000000000009;
                  address internal constant L2_STANDARD_BRIDGE = 0x4200000000000000000000000000000000000010;
                  address internal constant SEQUENCER_FEE_WALLET = 0x4200000000000000000000000000000000000011;
                  address internal constant L2_STANDARD_TOKEN_FACTORY =
                      0x4200000000000000000000000000000000000012;
                  address internal constant L1_BLOCK_NUMBER = 0x4200000000000000000000000000000000000013;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* External Imports */
              import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
              /**
               * @title Lib_AddressManager
               */
              contract Lib_AddressManager is Ownable {
                  /**********
                   * Events *
                   **********/
                  event AddressSet(string indexed _name, address _newAddress, address _oldAddress);
                  /*************
                   * Variables *
                   *************/
                  mapping(bytes32 => address) private addresses;
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Changes the address associated with a particular name.
                   * @param _name String name to associate an address with.
                   * @param _address Address to associate with the name.
                   */
                  function setAddress(string memory _name, address _address) external onlyOwner {
                      bytes32 nameHash = _getNameHash(_name);
                      address oldAddress = addresses[nameHash];
                      addresses[nameHash] = _address;
                      emit AddressSet(_name, _address, oldAddress);
                  }
                  /**
                   * Retrieves the address associated with a given name.
                   * @param _name Name to retrieve an address for.
                   * @return Address associated with the given name.
                   */
                  function getAddress(string memory _name) external view returns (address) {
                      return addresses[_getNameHash(_name)];
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Computes the hash of a name.
                   * @param _name Name to compute a hash for.
                   * @return Hash of the given name.
                   */
                  function _getNameHash(string memory _name) internal pure returns (bytes32) {
                      return keccak256(abi.encodePacked(_name));
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { Lib_AddressManager } from "./Lib_AddressManager.sol";
              /**
               * @title Lib_AddressResolver
               */
              abstract contract Lib_AddressResolver {
                  /*************
                   * Variables *
                   *************/
                  Lib_AddressManager public libAddressManager;
                  /***************
                   * Constructor *
                   ***************/
                  /**
                   * @param _libAddressManager Address of the Lib_AddressManager.
                   */
                  constructor(address _libAddressManager) {
                      libAddressManager = Lib_AddressManager(_libAddressManager);
                  }
                  /********************
                   * Public Functions *
                   ********************/
                  /**
                   * Resolves the address associated with a given name.
                   * @param _name Name to resolve an address for.
                   * @return Address associated with the given name.
                   */
                  function resolve(string memory _name) public view returns (address) {
                      return libAddressManager.getAddress(_name);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_RLPReader
               * @dev Adapted from "RLPReader" by Hamdi Allam ([email protected]).
               */
              library Lib_RLPReader {
                  /*************
                   * Constants *
                   *************/
                  uint256 internal constant MAX_LIST_LENGTH = 32;
                  /*********
                   * Enums *
                   *********/
                  enum RLPItemType {
                      DATA_ITEM,
                      LIST_ITEM
                  }
                  /***********
                   * Structs *
                   ***********/
                  struct RLPItem {
                      uint256 length;
                      uint256 ptr;
                  }
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Converts bytes to a reference to memory position and length.
                   * @param _in Input bytes to convert.
                   * @return Output memory reference.
                   */
                  function toRLPItem(bytes memory _in) internal pure returns (RLPItem memory) {
                      uint256 ptr;
                      assembly {
                          ptr := add(_in, 32)
                      }
                      return RLPItem({ length: _in.length, ptr: ptr });
                  }
                  /**
                   * Reads an RLP list value into a list of RLP items.
                   * @param _in RLP list value.
                   * @return Decoded RLP list items.
                   */
                  function readList(RLPItem memory _in) internal pure returns (RLPItem[] memory) {
                      (uint256 listOffset, , RLPItemType itemType) = _decodeLength(_in);
                      require(itemType == RLPItemType.LIST_ITEM, "Invalid RLP list value.");
                      // Solidity in-memory arrays can't be increased in size, but *can* be decreased in size by
                      // writing to the length. Since we can't know the number of RLP items without looping over
                      // the entire input, we'd have to loop twice to accurately size this array. It's easier to
                      // simply set a reasonable maximum list length and decrease the size before we finish.
                      RLPItem[] memory out = new RLPItem[](MAX_LIST_LENGTH);
                      uint256 itemCount = 0;
                      uint256 offset = listOffset;
                      while (offset < _in.length) {
                          require(itemCount < MAX_LIST_LENGTH, "Provided RLP list exceeds max list length.");
                          (uint256 itemOffset, uint256 itemLength, ) = _decodeLength(
                              RLPItem({ length: _in.length - offset, ptr: _in.ptr + offset })
                          );
                          out[itemCount] = RLPItem({ length: itemLength + itemOffset, ptr: _in.ptr + offset });
                          itemCount += 1;
                          offset += itemOffset + itemLength;
                      }
                      // Decrease the array size to match the actual item count.
                      assembly {
                          mstore(out, itemCount)
                      }
                      return out;
                  }
                  /**
                   * Reads an RLP list value into a list of RLP items.
                   * @param _in RLP list value.
                   * @return Decoded RLP list items.
                   */
                  function readList(bytes memory _in) internal pure returns (RLPItem[] memory) {
                      return readList(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP bytes value into bytes.
                   * @param _in RLP bytes value.
                   * @return Decoded bytes.
                   */
                  function readBytes(RLPItem memory _in) internal pure returns (bytes memory) {
                      (uint256 itemOffset, uint256 itemLength, RLPItemType itemType) = _decodeLength(_in);
                      require(itemType == RLPItemType.DATA_ITEM, "Invalid RLP bytes value.");
                      return _copy(_in.ptr, itemOffset, itemLength);
                  }
                  /**
                   * Reads an RLP bytes value into bytes.
                   * @param _in RLP bytes value.
                   * @return Decoded bytes.
                   */
                  function readBytes(bytes memory _in) internal pure returns (bytes memory) {
                      return readBytes(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP string value into a string.
                   * @param _in RLP string value.
                   * @return Decoded string.
                   */
                  function readString(RLPItem memory _in) internal pure returns (string memory) {
                      return string(readBytes(_in));
                  }
                  /**
                   * Reads an RLP string value into a string.
                   * @param _in RLP string value.
                   * @return Decoded string.
                   */
                  function readString(bytes memory _in) internal pure returns (string memory) {
                      return readString(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP bytes32 value into a bytes32.
                   * @param _in RLP bytes32 value.
                   * @return Decoded bytes32.
                   */
                  function readBytes32(RLPItem memory _in) internal pure returns (bytes32) {
                      require(_in.length <= 33, "Invalid RLP bytes32 value.");
                      (uint256 itemOffset, uint256 itemLength, RLPItemType itemType) = _decodeLength(_in);
                      require(itemType == RLPItemType.DATA_ITEM, "Invalid RLP bytes32 value.");
                      uint256 ptr = _in.ptr + itemOffset;
                      bytes32 out;
                      assembly {
                          out := mload(ptr)
                          // Shift the bytes over to match the item size.
                          if lt(itemLength, 32) {
                              out := div(out, exp(256, sub(32, itemLength)))
                          }
                      }
                      return out;
                  }
                  /**
                   * Reads an RLP bytes32 value into a bytes32.
                   * @param _in RLP bytes32 value.
                   * @return Decoded bytes32.
                   */
                  function readBytes32(bytes memory _in) internal pure returns (bytes32) {
                      return readBytes32(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP uint256 value into a uint256.
                   * @param _in RLP uint256 value.
                   * @return Decoded uint256.
                   */
                  function readUint256(RLPItem memory _in) internal pure returns (uint256) {
                      return uint256(readBytes32(_in));
                  }
                  /**
                   * Reads an RLP uint256 value into a uint256.
                   * @param _in RLP uint256 value.
                   * @return Decoded uint256.
                   */
                  function readUint256(bytes memory _in) internal pure returns (uint256) {
                      return readUint256(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP bool value into a bool.
                   * @param _in RLP bool value.
                   * @return Decoded bool.
                   */
                  function readBool(RLPItem memory _in) internal pure returns (bool) {
                      require(_in.length == 1, "Invalid RLP boolean value.");
                      uint256 ptr = _in.ptr;
                      uint256 out;
                      assembly {
                          out := byte(0, mload(ptr))
                      }
                      require(out == 0 || out == 1, "Lib_RLPReader: Invalid RLP boolean value, must be 0 or 1");
                      return out != 0;
                  }
                  /**
                   * Reads an RLP bool value into a bool.
                   * @param _in RLP bool value.
                   * @return Decoded bool.
                   */
                  function readBool(bytes memory _in) internal pure returns (bool) {
                      return readBool(toRLPItem(_in));
                  }
                  /**
                   * Reads an RLP address value into a address.
                   * @param _in RLP address value.
                   * @return Decoded address.
                   */
                  function readAddress(RLPItem memory _in) internal pure returns (address) {
                      if (_in.length == 1) {
                          return address(0);
                      }
                      require(_in.length == 21, "Invalid RLP address value.");
                      return address(uint160(readUint256(_in)));
                  }
                  /**
                   * Reads an RLP address value into a address.
                   * @param _in RLP address value.
                   * @return Decoded address.
                   */
                  function readAddress(bytes memory _in) internal pure returns (address) {
                      return readAddress(toRLPItem(_in));
                  }
                  /**
                   * Reads the raw bytes of an RLP item.
                   * @param _in RLP item to read.
                   * @return Raw RLP bytes.
                   */
                  function readRawBytes(RLPItem memory _in) internal pure returns (bytes memory) {
                      return _copy(_in);
                  }
                  /*********************
                   * Private Functions *
                   *********************/
                  /**
                   * Decodes the length of an RLP item.
                   * @param _in RLP item to decode.
                   * @return Offset of the encoded data.
                   * @return Length of the encoded data.
                   * @return RLP item type (LIST_ITEM or DATA_ITEM).
                   */
                  function _decodeLength(RLPItem memory _in)
                      private
                      pure
                      returns (
                          uint256,
                          uint256,
                          RLPItemType
                      )
                  {
                      require(_in.length > 0, "RLP item cannot be null.");
                      uint256 ptr = _in.ptr;
                      uint256 prefix;
                      assembly {
                          prefix := byte(0, mload(ptr))
                      }
                      if (prefix <= 0x7f) {
                          // Single byte.
                          return (0, 1, RLPItemType.DATA_ITEM);
                      } else if (prefix <= 0xb7) {
                          // Short string.
                          uint256 strLen = prefix - 0x80;
                          require(_in.length > strLen, "Invalid RLP short string.");
                          return (1, strLen, RLPItemType.DATA_ITEM);
                      } else if (prefix <= 0xbf) {
                          // Long string.
                          uint256 lenOfStrLen = prefix - 0xb7;
                          require(_in.length > lenOfStrLen, "Invalid RLP long string length.");
                          uint256 strLen;
                          assembly {
                              // Pick out the string length.
                              strLen := div(mload(add(ptr, 1)), exp(256, sub(32, lenOfStrLen)))
                          }
                          require(_in.length > lenOfStrLen + strLen, "Invalid RLP long string.");
                          return (1 + lenOfStrLen, strLen, RLPItemType.DATA_ITEM);
                      } else if (prefix <= 0xf7) {
                          // Short list.
                          uint256 listLen = prefix - 0xc0;
                          require(_in.length > listLen, "Invalid RLP short list.");
                          return (1, listLen, RLPItemType.LIST_ITEM);
                      } else {
                          // Long list.
                          uint256 lenOfListLen = prefix - 0xf7;
                          require(_in.length > lenOfListLen, "Invalid RLP long list length.");
                          uint256 listLen;
                          assembly {
                              // Pick out the list length.
                              listLen := div(mload(add(ptr, 1)), exp(256, sub(32, lenOfListLen)))
                          }
                          require(_in.length > lenOfListLen + listLen, "Invalid RLP long list.");
                          return (1 + lenOfListLen, listLen, RLPItemType.LIST_ITEM);
                      }
                  }
                  /**
                   * Copies the bytes from a memory location.
                   * @param _src Pointer to the location to read from.
                   * @param _offset Offset to start reading from.
                   * @param _length Number of bytes to read.
                   * @return Copied bytes.
                   */
                  function _copy(
                      uint256 _src,
                      uint256 _offset,
                      uint256 _length
                  ) private pure returns (bytes memory) {
                      bytes memory out = new bytes(_length);
                      if (out.length == 0) {
                          return out;
                      }
                      uint256 src = _src + _offset;
                      uint256 dest;
                      assembly {
                          dest := add(out, 32)
                      }
                      // Copy over as many complete words as we can.
                      for (uint256 i = 0; i < _length / 32; i++) {
                          assembly {
                              mstore(dest, mload(src))
                          }
                          src += 32;
                          dest += 32;
                      }
                      // Pick out the remaining bytes.
                      uint256 mask;
                      unchecked {
                          mask = 256**(32 - (_length % 32)) - 1;
                      }
                      assembly {
                          mstore(dest, or(and(mload(src), not(mask)), and(mload(dest), mask)))
                      }
                      return out;
                  }
                  /**
                   * Copies an RLP item into bytes.
                   * @param _in RLP item to copy.
                   * @return Copied bytes.
                   */
                  function _copy(RLPItem memory _in) private pure returns (bytes memory) {
                      return _copy(_in.ptr, 0, _in.length);
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_RLPWriter
               * @author Bakaoh (with modifications)
               */
              library Lib_RLPWriter {
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * RLP encodes a byte string.
                   * @param _in The byte string to encode.
                   * @return The RLP encoded string in bytes.
                   */
                  function writeBytes(bytes memory _in) internal pure returns (bytes memory) {
                      bytes memory encoded;
                      if (_in.length == 1 && uint8(_in[0]) < 128) {
                          encoded = _in;
                      } else {
                          encoded = abi.encodePacked(_writeLength(_in.length, 128), _in);
                      }
                      return encoded;
                  }
                  /**
                   * RLP encodes a list of RLP encoded byte byte strings.
                   * @param _in The list of RLP encoded byte strings.
                   * @return The RLP encoded list of items in bytes.
                   */
                  function writeList(bytes[] memory _in) internal pure returns (bytes memory) {
                      bytes memory list = _flatten(_in);
                      return abi.encodePacked(_writeLength(list.length, 192), list);
                  }
                  /**
                   * RLP encodes a string.
                   * @param _in The string to encode.
                   * @return The RLP encoded string in bytes.
                   */
                  function writeString(string memory _in) internal pure returns (bytes memory) {
                      return writeBytes(bytes(_in));
                  }
                  /**
                   * RLP encodes an address.
                   * @param _in The address to encode.
                   * @return The RLP encoded address in bytes.
                   */
                  function writeAddress(address _in) internal pure returns (bytes memory) {
                      return writeBytes(abi.encodePacked(_in));
                  }
                  /**
                   * RLP encodes a uint.
                   * @param _in The uint256 to encode.
                   * @return The RLP encoded uint256 in bytes.
                   */
                  function writeUint(uint256 _in) internal pure returns (bytes memory) {
                      return writeBytes(_toBinary(_in));
                  }
                  /**
                   * RLP encodes a bool.
                   * @param _in The bool to encode.
                   * @return The RLP encoded bool in bytes.
                   */
                  function writeBool(bool _in) internal pure returns (bytes memory) {
                      bytes memory encoded = new bytes(1);
                      encoded[0] = (_in ? bytes1(0x01) : bytes1(0x80));
                      return encoded;
                  }
                  /*********************
                   * Private Functions *
                   *********************/
                  /**
                   * Encode the first byte, followed by the `len` in binary form if `length` is more than 55.
                   * @param _len The length of the string or the payload.
                   * @param _offset 128 if item is string, 192 if item is list.
                   * @return RLP encoded bytes.
                   */
                  function _writeLength(uint256 _len, uint256 _offset) private pure returns (bytes memory) {
                      bytes memory encoded;
                      if (_len < 56) {
                          encoded = new bytes(1);
                          encoded[0] = bytes1(uint8(_len) + uint8(_offset));
                      } else {
                          uint256 lenLen;
                          uint256 i = 1;
                          while (_len / i != 0) {
                              lenLen++;
                              i *= 256;
                          }
                          encoded = new bytes(lenLen + 1);
                          encoded[0] = bytes1(uint8(lenLen) + uint8(_offset) + 55);
                          for (i = 1; i <= lenLen; i++) {
                              encoded[i] = bytes1(uint8((_len / (256**(lenLen - i))) % 256));
                          }
                      }
                      return encoded;
                  }
                  /**
                   * Encode integer in big endian binary form with no leading zeroes.
                   * @notice TODO: This should be optimized with assembly to save gas costs.
                   * @param _x The integer to encode.
                   * @return RLP encoded bytes.
                   */
                  function _toBinary(uint256 _x) private pure returns (bytes memory) {
                      bytes memory b = abi.encodePacked(_x);
                      uint256 i = 0;
                      for (; i < 32; i++) {
                          if (b[i] != 0) {
                              break;
                          }
                      }
                      bytes memory res = new bytes(32 - i);
                      for (uint256 j = 0; j < res.length; j++) {
                          res[j] = b[i++];
                      }
                      return res;
                  }
                  /**
                   * Copies a piece of memory to another location.
                   * @notice From: https://github.com/Arachnid/solidity-stringutils/blob/master/src/strings.sol.
                   * @param _dest Destination location.
                   * @param _src Source location.
                   * @param _len Length of memory to copy.
                   */
                  function _memcpy(
                      uint256 _dest,
                      uint256 _src,
                      uint256 _len
                  ) private pure {
                      uint256 dest = _dest;
                      uint256 src = _src;
                      uint256 len = _len;
                      for (; len >= 32; len -= 32) {
                          assembly {
                              mstore(dest, mload(src))
                          }
                          dest += 32;
                          src += 32;
                      }
                      uint256 mask;
                      unchecked {
                          mask = 256**(32 - len) - 1;
                      }
                      assembly {
                          let srcpart := and(mload(src), not(mask))
                          let destpart := and(mload(dest), mask)
                          mstore(dest, or(destpart, srcpart))
                      }
                  }
                  /**
                   * Flattens a list of byte strings into one byte string.
                   * @notice From: https://github.com/sammayo/solidity-rlp-encoder/blob/master/RLPEncode.sol.
                   * @param _list List of byte strings to flatten.
                   * @return The flattened byte string.
                   */
                  function _flatten(bytes[] memory _list) private pure returns (bytes memory) {
                      if (_list.length == 0) {
                          return new bytes(0);
                      }
                      uint256 len;
                      uint256 i = 0;
                      for (; i < _list.length; i++) {
                          len += _list[i].length;
                      }
                      bytes memory flattened = new bytes(len);
                      uint256 flattenedPtr;
                      assembly {
                          flattenedPtr := add(flattened, 0x20)
                      }
                      for (i = 0; i < _list.length; i++) {
                          bytes memory item = _list[i];
                          uint256 listPtr;
                          assembly {
                              listPtr := add(item, 0x20)
                          }
                          _memcpy(flattenedPtr, listPtr, item.length);
                          flattenedPtr += _list[i].length;
                      }
                      return flattened;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { Lib_BytesUtils } from "../utils/Lib_BytesUtils.sol";
              import { Lib_RLPReader } from "../rlp/Lib_RLPReader.sol";
              import { Lib_RLPWriter } from "../rlp/Lib_RLPWriter.sol";
              /**
               * @title Lib_MerkleTrie
               */
              library Lib_MerkleTrie {
                  /*******************
                   * Data Structures *
                   *******************/
                  enum NodeType {
                      BranchNode,
                      ExtensionNode,
                      LeafNode
                  }
                  struct TrieNode {
                      bytes encoded;
                      Lib_RLPReader.RLPItem[] decoded;
                  }
                  /**********************
                   * Contract Constants *
                   **********************/
                  // TREE_RADIX determines the number of elements per branch node.
                  uint256 constant TREE_RADIX = 16;
                  // Branch nodes have TREE_RADIX elements plus an additional `value` slot.
                  uint256 constant BRANCH_NODE_LENGTH = TREE_RADIX + 1;
                  // Leaf nodes and extension nodes always have two elements, a `path` and a `value`.
                  uint256 constant LEAF_OR_EXTENSION_NODE_LENGTH = 2;
                  // Prefixes are prepended to the `path` within a leaf or extension node and
                  // allow us to differentiate between the two node types. `ODD` or `EVEN` is
                  // determined by the number of nibbles within the unprefixed `path`. If the
                  // number of nibbles if even, we need to insert an extra padding nibble so
                  // the resulting prefixed `path` has an even number of nibbles.
                  uint8 constant PREFIX_EXTENSION_EVEN = 0;
                  uint8 constant PREFIX_EXTENSION_ODD = 1;
                  uint8 constant PREFIX_LEAF_EVEN = 2;
                  uint8 constant PREFIX_LEAF_ODD = 3;
                  // Just a utility constant. RLP represents `NULL` as 0x80.
                  bytes1 constant RLP_NULL = bytes1(0x80);
                  bytes constant RLP_NULL_BYTES = hex"80";
                  bytes32 internal constant KECCAK256_RLP_NULL_BYTES = keccak256(RLP_NULL_BYTES);
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * @notice Verifies a proof that a given key/value pair is present in the
                   * Merkle trie.
                   * @param _key Key of the node to search for, as a hex string.
                   * @param _value Value of the node to search for, as a hex string.
                   * @param _proof Merkle trie inclusion proof for the desired node. Unlike
                   * traditional Merkle trees, this proof is executed top-down and consists
                   * of a list of RLP-encoded nodes that make a path down to the target node.
                   * @param _root Known root of the Merkle trie. Used to verify that the
                   * included proof is correctly constructed.
                   * @return _verified `true` if the k/v pair exists in the trie, `false` otherwise.
                   */
                  function verifyInclusionProof(
                      bytes memory _key,
                      bytes memory _value,
                      bytes memory _proof,
                      bytes32 _root
                  ) internal pure returns (bool _verified) {
                      (bool exists, bytes memory value) = get(_key, _proof, _root);
                      return (exists && Lib_BytesUtils.equal(_value, value));
                  }
                  /**
                   * @notice Updates a Merkle trie and returns a new root hash.
                   * @param _key Key of the node to update, as a hex string.
                   * @param _value Value of the node to update, as a hex string.
                   * @param _proof Merkle trie inclusion proof for the node *nearest* the
                   * target node. If the key exists, we can simply update the value.
                   * Otherwise, we need to modify the trie to handle the new k/v pair.
                   * @param _root Known root of the Merkle trie. Used to verify that the
                   * included proof is correctly constructed.
                   * @return _updatedRoot Root hash of the newly constructed trie.
                   */
                  function update(
                      bytes memory _key,
                      bytes memory _value,
                      bytes memory _proof,
                      bytes32 _root
                  ) internal pure returns (bytes32 _updatedRoot) {
                      // Special case when inserting the very first node.
                      if (_root == KECCAK256_RLP_NULL_BYTES) {
                          return getSingleNodeRootHash(_key, _value);
                      }
                      TrieNode[] memory proof = _parseProof(_proof);
                      (uint256 pathLength, bytes memory keyRemainder, ) = _walkNodePath(proof, _key, _root);
                      TrieNode[] memory newPath = _getNewPath(proof, pathLength, _key, keyRemainder, _value);
                      return _getUpdatedTrieRoot(newPath, _key);
                  }
                  /**
                   * @notice Retrieves the value associated with a given key.
                   * @param _key Key to search for, as hex bytes.
                   * @param _proof Merkle trie inclusion proof for the key.
                   * @param _root Known root of the Merkle trie.
                   * @return _exists Whether or not the key exists.
                   * @return _value Value of the key if it exists.
                   */
                  function get(
                      bytes memory _key,
                      bytes memory _proof,
                      bytes32 _root
                  ) internal pure returns (bool _exists, bytes memory _value) {
                      TrieNode[] memory proof = _parseProof(_proof);
                      (uint256 pathLength, bytes memory keyRemainder, bool isFinalNode) = _walkNodePath(
                          proof,
                          _key,
                          _root
                      );
                      bool exists = keyRemainder.length == 0;
                      require(exists || isFinalNode, "Provided proof is invalid.");
                      bytes memory value = exists ? _getNodeValue(proof[pathLength - 1]) : bytes("");
                      return (exists, value);
                  }
                  /**
                   * Computes the root hash for a trie with a single node.
                   * @param _key Key for the single node.
                   * @param _value Value for the single node.
                   * @return _updatedRoot Hash of the trie.
                   */
                  function getSingleNodeRootHash(bytes memory _key, bytes memory _value)
                      internal
                      pure
                      returns (bytes32 _updatedRoot)
                  {
                      return keccak256(_makeLeafNode(Lib_BytesUtils.toNibbles(_key), _value).encoded);
                  }
                  /*********************
                   * Private Functions *
                   *********************/
                  /**
                   * @notice Walks through a proof using a provided key.
                   * @param _proof Inclusion proof to walk through.
                   * @param _key Key to use for the walk.
                   * @param _root Known root of the trie.
                   * @return _pathLength Length of the final path
                   * @return _keyRemainder Portion of the key remaining after the walk.
                   * @return _isFinalNode Whether or not we've hit a dead end.
                   */
                  function _walkNodePath(
                      TrieNode[] memory _proof,
                      bytes memory _key,
                      bytes32 _root
                  )
                      private
                      pure
                      returns (
                          uint256 _pathLength,
                          bytes memory _keyRemainder,
                          bool _isFinalNode
                      )
                  {
                      uint256 pathLength = 0;
                      bytes memory key = Lib_BytesUtils.toNibbles(_key);
                      bytes32 currentNodeID = _root;
                      uint256 currentKeyIndex = 0;
                      uint256 currentKeyIncrement = 0;
                      TrieNode memory currentNode;
                      // Proof is top-down, so we start at the first element (root).
                      for (uint256 i = 0; i < _proof.length; i++) {
                          currentNode = _proof[i];
                          currentKeyIndex += currentKeyIncrement;
                          // Keep track of the proof elements we actually need.
                          // It's expensive to resize arrays, so this simply reduces gas costs.
                          pathLength += 1;
                          if (currentKeyIndex == 0) {
                              // First proof element is always the root node.
                              require(keccak256(currentNode.encoded) == currentNodeID, "Invalid root hash");
                          } else if (currentNode.encoded.length >= 32) {
                              // Nodes 32 bytes or larger are hashed inside branch nodes.
                              require(
                                  keccak256(currentNode.encoded) == currentNodeID,
                                  "Invalid large internal hash"
                              );
                          } else {
                              // Nodes smaller than 31 bytes aren't hashed.
                              require(
                                  Lib_BytesUtils.toBytes32(currentNode.encoded) == currentNodeID,
                                  "Invalid internal node hash"
                              );
                          }
                          if (currentNode.decoded.length == BRANCH_NODE_LENGTH) {
                              if (currentKeyIndex == key.length) {
                                  // We've hit the end of the key
                                  // meaning the value should be within this branch node.
                                  break;
                              } else {
                                  // We're not at the end of the key yet.
                                  // Figure out what the next node ID should be and continue.
                                  uint8 branchKey = uint8(key[currentKeyIndex]);
                                  Lib_RLPReader.RLPItem memory nextNode = currentNode.decoded[branchKey];
                                  currentNodeID = _getNodeID(nextNode);
                                  currentKeyIncrement = 1;
                                  continue;
                              }
                          } else if (currentNode.decoded.length == LEAF_OR_EXTENSION_NODE_LENGTH) {
                              bytes memory path = _getNodePath(currentNode);
                              uint8 prefix = uint8(path[0]);
                              uint8 offset = 2 - (prefix % 2);
                              bytes memory pathRemainder = Lib_BytesUtils.slice(path, offset);
                              bytes memory keyRemainder = Lib_BytesUtils.slice(key, currentKeyIndex);
                              uint256 sharedNibbleLength = _getSharedNibbleLength(pathRemainder, keyRemainder);
                              if (prefix == PREFIX_LEAF_EVEN || prefix == PREFIX_LEAF_ODD) {
                                  if (
                                      pathRemainder.length == sharedNibbleLength &&
                                      keyRemainder.length == sharedNibbleLength
                                  ) {
                                      // The key within this leaf matches our key exactly.
                                      // Increment the key index to reflect that we have no remainder.
                                      currentKeyIndex += sharedNibbleLength;
                                  }
                                  // We've hit a leaf node, so our next node should be NULL.
                                  currentNodeID = bytes32(RLP_NULL);
                                  break;
                              } else if (prefix == PREFIX_EXTENSION_EVEN || prefix == PREFIX_EXTENSION_ODD) {
                                  if (sharedNibbleLength != pathRemainder.length) {
                                      // Our extension node is not identical to the remainder.
                                      // We've hit the end of this path
                                      // updates will need to modify this extension.
                                      currentNodeID = bytes32(RLP_NULL);
                                      break;
                                  } else {
                                      // Our extension shares some nibbles.
                                      // Carry on to the next node.
                                      currentNodeID = _getNodeID(currentNode.decoded[1]);
                                      currentKeyIncrement = sharedNibbleLength;
                                      continue;
                                  }
                              } else {
                                  revert("Received a node with an unknown prefix");
                              }
                          } else {
                              revert("Received an unparseable node.");
                          }
                      }
                      // If our node ID is NULL, then we're at a dead end.
                      bool isFinalNode = currentNodeID == bytes32(RLP_NULL);
                      return (pathLength, Lib_BytesUtils.slice(key, currentKeyIndex), isFinalNode);
                  }
                  /**
                   * @notice Creates new nodes to support a k/v pair insertion into a given Merkle trie path.
                   * @param _path Path to the node nearest the k/v pair.
                   * @param _pathLength Length of the path. Necessary because the provided path may include
                   *  additional nodes (e.g., it comes directly from a proof) and we can't resize in-memory
                   *  arrays without costly duplication.
                   * @param _key Full original key.
                   * @param _keyRemainder Portion of the initial key that must be inserted into the trie.
                   * @param _value Value to insert at the given key.
                   * @return _newPath A new path with the inserted k/v pair and extra supporting nodes.
                   */
                  function _getNewPath(
                      TrieNode[] memory _path,
                      uint256 _pathLength,
                      bytes memory _key,
                      bytes memory _keyRemainder,
                      bytes memory _value
                  ) private pure returns (TrieNode[] memory _newPath) {
                      bytes memory keyRemainder = _keyRemainder;
                      // Most of our logic depends on the status of the last node in the path.
                      TrieNode memory lastNode = _path[_pathLength - 1];
                      NodeType lastNodeType = _getNodeType(lastNode);
                      // Create an array for newly created nodes.
                      // We need up to three new nodes, depending on the contents of the last node.
                      // Since array resizing is expensive, we'll keep track of the size manually.
                      // We're using an explicit `totalNewNodes += 1` after insertions for clarity.
                      TrieNode[] memory newNodes = new TrieNode[](3);
                      uint256 totalNewNodes = 0;
                      // solhint-disable-next-line max-line-length
                      // Reference: https://github.com/ethereumjs/merkle-patricia-tree/blob/c0a10395aab37d42c175a47114ebfcbd7efcf059/src/baseTrie.ts#L294-L313
                      bool matchLeaf = false;
                      if (lastNodeType == NodeType.LeafNode) {
                          uint256 l = 0;
                          if (_path.length > 0) {
                              for (uint256 i = 0; i < _path.length - 1; i++) {
                                  if (_getNodeType(_path[i]) == NodeType.BranchNode) {
                                      l++;
                                  } else {
                                      l += _getNodeKey(_path[i]).length;
                                  }
                              }
                          }
                          if (
                              _getSharedNibbleLength(
                                  _getNodeKey(lastNode),
                                  Lib_BytesUtils.slice(Lib_BytesUtils.toNibbles(_key), l)
                              ) ==
                              _getNodeKey(lastNode).length &&
                              keyRemainder.length == 0
                          ) {
                              matchLeaf = true;
                          }
                      }
                      if (matchLeaf) {
                          // We've found a leaf node with the given key.
                          // Simply need to update the value of the node to match.
                          newNodes[totalNewNodes] = _makeLeafNode(_getNodeKey(lastNode), _value);
                          totalNewNodes += 1;
                      } else if (lastNodeType == NodeType.BranchNode) {
                          if (keyRemainder.length == 0) {
                              // We've found a branch node with the given key.
                              // Simply need to update the value of the node to match.
                              newNodes[totalNewNodes] = _editBranchValue(lastNode, _value);
                              totalNewNodes += 1;
                          } else {
                              // We've found a branch node, but it doesn't contain our key.
                              // Reinsert the old branch for now.
                              newNodes[totalNewNodes] = lastNode;
                              totalNewNodes += 1;
                              // Create a new leaf node, slicing our remainder since the first byte points
                              // to our branch node.
                              newNodes[totalNewNodes] = _makeLeafNode(
                                  Lib_BytesUtils.slice(keyRemainder, 1),
                                  _value
                              );
                              totalNewNodes += 1;
                          }
                      } else {
                          // Our last node is either an extension node or a leaf node with a different key.
                          bytes memory lastNodeKey = _getNodeKey(lastNode);
                          uint256 sharedNibbleLength = _getSharedNibbleLength(lastNodeKey, keyRemainder);
                          if (sharedNibbleLength != 0) {
                              // We've got some shared nibbles between the last node and our key remainder.
                              // We'll need to insert an extension node that covers these shared nibbles.
                              bytes memory nextNodeKey = Lib_BytesUtils.slice(lastNodeKey, 0, sharedNibbleLength);
                              newNodes[totalNewNodes] = _makeExtensionNode(nextNodeKey, _getNodeHash(_value));
                              totalNewNodes += 1;
                              // Cut down the keys since we've just covered these shared nibbles.
                              lastNodeKey = Lib_BytesUtils.slice(lastNodeKey, sharedNibbleLength);
                              keyRemainder = Lib_BytesUtils.slice(keyRemainder, sharedNibbleLength);
                          }
                          // Create an empty branch to fill in.
                          TrieNode memory newBranch = _makeEmptyBranchNode();
                          if (lastNodeKey.length == 0) {
                              // Key remainder was larger than the key for our last node.
                              // The value within our last node is therefore going to be shifted into
                              // a branch value slot.
                              newBranch = _editBranchValue(newBranch, _getNodeValue(lastNode));
                          } else {
                              // Last node key was larger than the key remainder.
                              // We're going to modify some index of our branch.
                              uint8 branchKey = uint8(lastNodeKey[0]);
                              // Move on to the next nibble.
                              lastNodeKey = Lib_BytesUtils.slice(lastNodeKey, 1);
                              if (lastNodeType == NodeType.LeafNode) {
                                  // We're dealing with a leaf node.
                                  // We'll modify the key and insert the old leaf node into the branch index.
                                  TrieNode memory modifiedLastNode = _makeLeafNode(
                                      lastNodeKey,
                                      _getNodeValue(lastNode)
                                  );
                                  newBranch = _editBranchIndex(
                                      newBranch,
                                      branchKey,
                                      _getNodeHash(modifiedLastNode.encoded)
                                  );
                              } else if (lastNodeKey.length != 0) {
                                  // We're dealing with a shrinking extension node.
                                  // We need to modify the node to decrease the size of the key.
                                  TrieNode memory modifiedLastNode = _makeExtensionNode(
                                      lastNodeKey,
                                      _getNodeValue(lastNode)
                                  );
                                  newBranch = _editBranchIndex(
                                      newBranch,
                                      branchKey,
                                      _getNodeHash(modifiedLastNode.encoded)
                                  );
                              } else {
                                  // We're dealing with an unnecessary extension node.
                                  // We're going to delete the node entirely.
                                  // Simply insert its current value into the branch index.
                                  newBranch = _editBranchIndex(newBranch, branchKey, _getNodeValue(lastNode));
                              }
                          }
                          if (keyRemainder.length == 0) {
                              // We've got nothing left in the key remainder.
                              // Simply insert the value into the branch value slot.
                              newBranch = _editBranchValue(newBranch, _value);
                              // Push the branch into the list of new nodes.
                              newNodes[totalNewNodes] = newBranch;
                              totalNewNodes += 1;
                          } else {
                              // We've got some key remainder to work with.
                              // We'll be inserting a leaf node into the trie.
                              // First, move on to the next nibble.
                              keyRemainder = Lib_BytesUtils.slice(keyRemainder, 1);
                              // Push the branch into the list of new nodes.
                              newNodes[totalNewNodes] = newBranch;
                              totalNewNodes += 1;
                              // Push a new leaf node for our k/v pair.
                              newNodes[totalNewNodes] = _makeLeafNode(keyRemainder, _value);
                              totalNewNodes += 1;
                          }
                      }
                      // Finally, join the old path with our newly created nodes.
                      // Since we're overwriting the last node in the path, we use `_pathLength - 1`.
                      return _joinNodeArrays(_path, _pathLength - 1, newNodes, totalNewNodes);
                  }
                  /**
                   * @notice Computes the trie root from a given path.
                   * @param _nodes Path to some k/v pair.
                   * @param _key Key for the k/v pair.
                   * @return _updatedRoot Root hash for the updated trie.
                   */
                  function _getUpdatedTrieRoot(TrieNode[] memory _nodes, bytes memory _key)
                      private
                      pure
                      returns (bytes32 _updatedRoot)
                  {
                      bytes memory key = Lib_BytesUtils.toNibbles(_key);
                      // Some variables to keep track of during iteration.
                      TrieNode memory currentNode;
                      NodeType currentNodeType;
                      bytes memory previousNodeHash;
                      // Run through the path backwards to rebuild our root hash.
                      for (uint256 i = _nodes.length; i > 0; i--) {
                          // Pick out the current node.
                          currentNode = _nodes[i - 1];
                          currentNodeType = _getNodeType(currentNode);
                          if (currentNodeType == NodeType.LeafNode) {
                              // Leaf nodes are already correctly encoded.
                              // Shift the key over to account for the nodes key.
                              bytes memory nodeKey = _getNodeKey(currentNode);
                              key = Lib_BytesUtils.slice(key, 0, key.length - nodeKey.length);
                          } else if (currentNodeType == NodeType.ExtensionNode) {
                              // Shift the key over to account for the nodes key.
                              bytes memory nodeKey = _getNodeKey(currentNode);
                              key = Lib_BytesUtils.slice(key, 0, key.length - nodeKey.length);
                              // If this node is the last element in the path, it'll be correctly encoded
                              // and we can skip this part.
                              if (previousNodeHash.length > 0) {
                                  // Re-encode the node based on the previous node.
                                  currentNode = _editExtensionNodeValue(currentNode, previousNodeHash);
                              }
                          } else if (currentNodeType == NodeType.BranchNode) {
                              // If this node is the last element in the path, it'll be correctly encoded
                              // and we can skip this part.
                              if (previousNodeHash.length > 0) {
                                  // Re-encode the node based on the previous node.
                                  uint8 branchKey = uint8(key[key.length - 1]);
                                  key = Lib_BytesUtils.slice(key, 0, key.length - 1);
                                  currentNode = _editBranchIndex(currentNode, branchKey, previousNodeHash);
                              }
                          }
                          // Compute the node hash for the next iteration.
                          previousNodeHash = _getNodeHash(currentNode.encoded);
                      }
                      // Current node should be the root at this point.
                      // Simply return the hash of its encoding.
                      return keccak256(currentNode.encoded);
                  }
                  /**
                   * @notice Parses an RLP-encoded proof into something more useful.
                   * @param _proof RLP-encoded proof to parse.
                   * @return _parsed Proof parsed into easily accessible structs.
                   */
                  function _parseProof(bytes memory _proof) private pure returns (TrieNode[] memory _parsed) {
                      Lib_RLPReader.RLPItem[] memory nodes = Lib_RLPReader.readList(_proof);
                      TrieNode[] memory proof = new TrieNode[](nodes.length);
                      for (uint256 i = 0; i < nodes.length; i++) {
                          bytes memory encoded = Lib_RLPReader.readBytes(nodes[i]);
                          proof[i] = TrieNode({ encoded: encoded, decoded: Lib_RLPReader.readList(encoded) });
                      }
                      return proof;
                  }
                  /**
                   * @notice Picks out the ID for a node. Node ID is referred to as the
                   * "hash" within the specification, but nodes < 32 bytes are not actually
                   * hashed.
                   * @param _node Node to pull an ID for.
                   * @return _nodeID ID for the node, depending on the size of its contents.
                   */
                  function _getNodeID(Lib_RLPReader.RLPItem memory _node) private pure returns (bytes32 _nodeID) {
                      bytes memory nodeID;
                      if (_node.length < 32) {
                          // Nodes smaller than 32 bytes are RLP encoded.
                          nodeID = Lib_RLPReader.readRawBytes(_node);
                      } else {
                          // Nodes 32 bytes or larger are hashed.
                          nodeID = Lib_RLPReader.readBytes(_node);
                      }
                      return Lib_BytesUtils.toBytes32(nodeID);
                  }
                  /**
                   * @notice Gets the path for a leaf or extension node.
                   * @param _node Node to get a path for.
                   * @return _path Node path, converted to an array of nibbles.
                   */
                  function _getNodePath(TrieNode memory _node) private pure returns (bytes memory _path) {
                      return Lib_BytesUtils.toNibbles(Lib_RLPReader.readBytes(_node.decoded[0]));
                  }
                  /**
                   * @notice Gets the key for a leaf or extension node. Keys are essentially
                   * just paths without any prefix.
                   * @param _node Node to get a key for.
                   * @return _key Node key, converted to an array of nibbles.
                   */
                  function _getNodeKey(TrieNode memory _node) private pure returns (bytes memory _key) {
                      return _removeHexPrefix(_getNodePath(_node));
                  }
                  /**
                   * @notice Gets the path for a node.
                   * @param _node Node to get a value for.
                   * @return _value Node value, as hex bytes.
                   */
                  function _getNodeValue(TrieNode memory _node) private pure returns (bytes memory _value) {
                      return Lib_RLPReader.readBytes(_node.decoded[_node.decoded.length - 1]);
                  }
                  /**
                   * @notice Computes the node hash for an encoded node. Nodes < 32 bytes
                   * are not hashed, all others are keccak256 hashed.
                   * @param _encoded Encoded node to hash.
                   * @return _hash Hash of the encoded node. Simply the input if < 32 bytes.
                   */
                  function _getNodeHash(bytes memory _encoded) private pure returns (bytes memory _hash) {
                      if (_encoded.length < 32) {
                          return _encoded;
                      } else {
                          return abi.encodePacked(keccak256(_encoded));
                      }
                  }
                  /**
                   * @notice Determines the type for a given node.
                   * @param _node Node to determine a type for.
                   * @return _type Type of the node; BranchNode/ExtensionNode/LeafNode.
                   */
                  function _getNodeType(TrieNode memory _node) private pure returns (NodeType _type) {
                      if (_node.decoded.length == BRANCH_NODE_LENGTH) {
                          return NodeType.BranchNode;
                      } else if (_node.decoded.length == LEAF_OR_EXTENSION_NODE_LENGTH) {
                          bytes memory path = _getNodePath(_node);
                          uint8 prefix = uint8(path[0]);
                          if (prefix == PREFIX_LEAF_EVEN || prefix == PREFIX_LEAF_ODD) {
                              return NodeType.LeafNode;
                          } else if (prefix == PREFIX_EXTENSION_EVEN || prefix == PREFIX_EXTENSION_ODD) {
                              return NodeType.ExtensionNode;
                          }
                      }
                      revert("Invalid node type");
                  }
                  /**
                   * @notice Utility; determines the number of nibbles shared between two
                   * nibble arrays.
                   * @param _a First nibble array.
                   * @param _b Second nibble array.
                   * @return _shared Number of shared nibbles.
                   */
                  function _getSharedNibbleLength(bytes memory _a, bytes memory _b)
                      private
                      pure
                      returns (uint256 _shared)
                  {
                      uint256 i = 0;
                      while (_a.length > i && _b.length > i && _a[i] == _b[i]) {
                          i++;
                      }
                      return i;
                  }
                  /**
                   * @notice Utility; converts an RLP-encoded node into our nice struct.
                   * @param _raw RLP-encoded node to convert.
                   * @return _node Node as a TrieNode struct.
                   */
                  function _makeNode(bytes[] memory _raw) private pure returns (TrieNode memory _node) {
                      bytes memory encoded = Lib_RLPWriter.writeList(_raw);
                      return TrieNode({ encoded: encoded, decoded: Lib_RLPReader.readList(encoded) });
                  }
                  /**
                   * @notice Utility; converts an RLP-decoded node into our nice struct.
                   * @param _items RLP-decoded node to convert.
                   * @return _node Node as a TrieNode struct.
                   */
                  function _makeNode(Lib_RLPReader.RLPItem[] memory _items)
                      private
                      pure
                      returns (TrieNode memory _node)
                  {
                      bytes[] memory raw = new bytes[](_items.length);
                      for (uint256 i = 0; i < _items.length; i++) {
                          raw[i] = Lib_RLPReader.readRawBytes(_items[i]);
                      }
                      return _makeNode(raw);
                  }
                  /**
                   * @notice Creates a new extension node.
                   * @param _key Key for the extension node, unprefixed.
                   * @param _value Value for the extension node.
                   * @return _node New extension node with the given k/v pair.
                   */
                  function _makeExtensionNode(bytes memory _key, bytes memory _value)
                      private
                      pure
                      returns (TrieNode memory _node)
                  {
                      bytes[] memory raw = new bytes[](2);
                      bytes memory key = _addHexPrefix(_key, false);
                      raw[0] = Lib_RLPWriter.writeBytes(Lib_BytesUtils.fromNibbles(key));
                      raw[1] = Lib_RLPWriter.writeBytes(_value);
                      return _makeNode(raw);
                  }
                  /**
                   * Creates a new extension node with the same key but a different value.
                   * @param _node Extension node to copy and modify.
                   * @param _value New value for the extension node.
                   * @return New node with the same key and different value.
                   */
                  function _editExtensionNodeValue(TrieNode memory _node, bytes memory _value)
                      private
                      pure
                      returns (TrieNode memory)
                  {
                      bytes[] memory raw = new bytes[](2);
                      bytes memory key = _addHexPrefix(_getNodeKey(_node), false);
                      raw[0] = Lib_RLPWriter.writeBytes(Lib_BytesUtils.fromNibbles(key));
                      if (_value.length < 32) {
                          raw[1] = _value;
                      } else {
                          raw[1] = Lib_RLPWriter.writeBytes(_value);
                      }
                      return _makeNode(raw);
                  }
                  /**
                   * @notice Creates a new leaf node.
                   * @dev This function is essentially identical to `_makeExtensionNode`.
                   * Although we could route both to a single method with a flag, it's
                   * more gas efficient to keep them separate and duplicate the logic.
                   * @param _key Key for the leaf node, unprefixed.
                   * @param _value Value for the leaf node.
                   * @return _node New leaf node with the given k/v pair.
                   */
                  function _makeLeafNode(bytes memory _key, bytes memory _value)
                      private
                      pure
                      returns (TrieNode memory _node)
                  {
                      bytes[] memory raw = new bytes[](2);
                      bytes memory key = _addHexPrefix(_key, true);
                      raw[0] = Lib_RLPWriter.writeBytes(Lib_BytesUtils.fromNibbles(key));
                      raw[1] = Lib_RLPWriter.writeBytes(_value);
                      return _makeNode(raw);
                  }
                  /**
                   * @notice Creates an empty branch node.
                   * @return _node Empty branch node as a TrieNode struct.
                   */
                  function _makeEmptyBranchNode() private pure returns (TrieNode memory _node) {
                      bytes[] memory raw = new bytes[](BRANCH_NODE_LENGTH);
                      for (uint256 i = 0; i < raw.length; i++) {
                          raw[i] = RLP_NULL_BYTES;
                      }
                      return _makeNode(raw);
                  }
                  /**
                   * @notice Modifies the value slot for a given branch.
                   * @param _branch Branch node to modify.
                   * @param _value Value to insert into the branch.
                   * @return _updatedNode Modified branch node.
                   */
                  function _editBranchValue(TrieNode memory _branch, bytes memory _value)
                      private
                      pure
                      returns (TrieNode memory _updatedNode)
                  {
                      bytes memory encoded = Lib_RLPWriter.writeBytes(_value);
                      _branch.decoded[_branch.decoded.length - 1] = Lib_RLPReader.toRLPItem(encoded);
                      return _makeNode(_branch.decoded);
                  }
                  /**
                   * @notice Modifies a slot at an index for a given branch.
                   * @param _branch Branch node to modify.
                   * @param _index Slot index to modify.
                   * @param _value Value to insert into the slot.
                   * @return _updatedNode Modified branch node.
                   */
                  function _editBranchIndex(
                      TrieNode memory _branch,
                      uint8 _index,
                      bytes memory _value
                  ) private pure returns (TrieNode memory _updatedNode) {
                      bytes memory encoded = _value.length < 32 ? _value : Lib_RLPWriter.writeBytes(_value);
                      _branch.decoded[_index] = Lib_RLPReader.toRLPItem(encoded);
                      return _makeNode(_branch.decoded);
                  }
                  /**
                   * @notice Utility; adds a prefix to a key.
                   * @param _key Key to prefix.
                   * @param _isLeaf Whether or not the key belongs to a leaf.
                   * @return _prefixedKey Prefixed key.
                   */
                  function _addHexPrefix(bytes memory _key, bool _isLeaf)
                      private
                      pure
                      returns (bytes memory _prefixedKey)
                  {
                      uint8 prefix = _isLeaf ? uint8(0x02) : uint8(0x00);
                      uint8 offset = uint8(_key.length % 2);
                      bytes memory prefixed = new bytes(2 - offset);
                      prefixed[0] = bytes1(prefix + offset);
                      return abi.encodePacked(prefixed, _key);
                  }
                  /**
                   * @notice Utility; removes a prefix from a path.
                   * @param _path Path to remove the prefix from.
                   * @return _unprefixedKey Unprefixed key.
                   */
                  function _removeHexPrefix(bytes memory _path)
                      private
                      pure
                      returns (bytes memory _unprefixedKey)
                  {
                      if (uint8(_path[0]) % 2 == 0) {
                          return Lib_BytesUtils.slice(_path, 2);
                      } else {
                          return Lib_BytesUtils.slice(_path, 1);
                      }
                  }
                  /**
                   * @notice Utility; combines two node arrays. Array lengths are required
                   * because the actual lengths may be longer than the filled lengths.
                   * Array resizing is extremely costly and should be avoided.
                   * @param _a First array to join.
                   * @param _aLength Length of the first array.
                   * @param _b Second array to join.
                   * @param _bLength Length of the second array.
                   * @return _joined Combined node array.
                   */
                  function _joinNodeArrays(
                      TrieNode[] memory _a,
                      uint256 _aLength,
                      TrieNode[] memory _b,
                      uint256 _bLength
                  ) private pure returns (TrieNode[] memory _joined) {
                      TrieNode[] memory ret = new TrieNode[](_aLength + _bLength);
                      // Copy elements from the first array.
                      for (uint256 i = 0; i < _aLength; i++) {
                          ret[i] = _a[i];
                      }
                      // Copy elements from the second array.
                      for (uint256 i = 0; i < _bLength; i++) {
                          ret[i + _aLength] = _b[i];
                      }
                      return ret;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /* Library Imports */
              import { Lib_MerkleTrie } from "./Lib_MerkleTrie.sol";
              /**
               * @title Lib_SecureMerkleTrie
               */
              library Lib_SecureMerkleTrie {
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * @notice Verifies a proof that a given key/value pair is present in the
                   * Merkle trie.
                   * @param _key Key of the node to search for, as a hex string.
                   * @param _value Value of the node to search for, as a hex string.
                   * @param _proof Merkle trie inclusion proof for the desired node. Unlike
                   * traditional Merkle trees, this proof is executed top-down and consists
                   * of a list of RLP-encoded nodes that make a path down to the target node.
                   * @param _root Known root of the Merkle trie. Used to verify that the
                   * included proof is correctly constructed.
                   * @return _verified `true` if the k/v pair exists in the trie, `false` otherwise.
                   */
                  function verifyInclusionProof(
                      bytes memory _key,
                      bytes memory _value,
                      bytes memory _proof,
                      bytes32 _root
                  ) internal pure returns (bool _verified) {
                      bytes memory key = _getSecureKey(_key);
                      return Lib_MerkleTrie.verifyInclusionProof(key, _value, _proof, _root);
                  }
                  /**
                   * @notice Updates a Merkle trie and returns a new root hash.
                   * @param _key Key of the node to update, as a hex string.
                   * @param _value Value of the node to update, as a hex string.
                   * @param _proof Merkle trie inclusion proof for the node *nearest* the
                   * target node. If the key exists, we can simply update the value.
                   * Otherwise, we need to modify the trie to handle the new k/v pair.
                   * @param _root Known root of the Merkle trie. Used to verify that the
                   * included proof is correctly constructed.
                   * @return _updatedRoot Root hash of the newly constructed trie.
                   */
                  function update(
                      bytes memory _key,
                      bytes memory _value,
                      bytes memory _proof,
                      bytes32 _root
                  ) internal pure returns (bytes32 _updatedRoot) {
                      bytes memory key = _getSecureKey(_key);
                      return Lib_MerkleTrie.update(key, _value, _proof, _root);
                  }
                  /**
                   * @notice Retrieves the value associated with a given key.
                   * @param _key Key to search for, as hex bytes.
                   * @param _proof Merkle trie inclusion proof for the key.
                   * @param _root Known root of the Merkle trie.
                   * @return _exists Whether or not the key exists.
                   * @return _value Value of the key if it exists.
                   */
                  function get(
                      bytes memory _key,
                      bytes memory _proof,
                      bytes32 _root
                  ) internal pure returns (bool _exists, bytes memory _value) {
                      bytes memory key = _getSecureKey(_key);
                      return Lib_MerkleTrie.get(key, _proof, _root);
                  }
                  /**
                   * Computes the root hash for a trie with a single node.
                   * @param _key Key for the single node.
                   * @param _value Value for the single node.
                   * @return _updatedRoot Hash of the trie.
                   */
                  function getSingleNodeRootHash(bytes memory _key, bytes memory _value)
                      internal
                      pure
                      returns (bytes32 _updatedRoot)
                  {
                      bytes memory key = _getSecureKey(_key);
                      return Lib_MerkleTrie.getSingleNodeRootHash(key, _value);
                  }
                  /*********************
                   * Private Functions *
                   *********************/
                  /**
                   * Computes the secure counterpart to a key.
                   * @param _key Key to get a secure key from.
                   * @return _secureKey Secure version of the key.
                   */
                  function _getSecureKey(bytes memory _key) private pure returns (bytes memory _secureKey) {
                      return abi.encodePacked(keccak256(_key));
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_Byte32Utils
               */
              library Lib_Bytes32Utils {
                  /**********************
                   * Internal Functions *
                   **********************/
                  /**
                   * Converts a bytes32 value to a boolean. Anything non-zero will be converted to "true."
                   * @param _in Input bytes32 value.
                   * @return Bytes32 as a boolean.
                   */
                  function toBool(bytes32 _in) internal pure returns (bool) {
                      return _in != 0;
                  }
                  /**
                   * Converts a boolean to a bytes32 value.
                   * @param _in Input boolean value.
                   * @return Boolean as a bytes32.
                   */
                  function fromBool(bool _in) internal pure returns (bytes32) {
                      return bytes32(uint256(_in ? 1 : 0));
                  }
                  /**
                   * Converts a bytes32 value to an address. Takes the *last* 20 bytes.
                   * @param _in Input bytes32 value.
                   * @return Bytes32 as an address.
                   */
                  function toAddress(bytes32 _in) internal pure returns (address) {
                      return address(uint160(uint256(_in)));
                  }
                  /**
                   * Converts an address to a bytes32.
                   * @param _in Input address value.
                   * @return Address as a bytes32.
                   */
                  function fromAddress(address _in) internal pure returns (bytes32) {
                      return bytes32(uint256(uint160(_in)));
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.9;
              /**
               * @title Lib_BytesUtils
               */
              library Lib_BytesUtils {
                  /**********************
                   * Internal Functions *
                   **********************/
                  function slice(
                      bytes memory _bytes,
                      uint256 _start,
                      uint256 _length
                  ) internal pure returns (bytes memory) {
                      require(_length + 31 >= _length, "slice_overflow");
                      require(_start + _length >= _start, "slice_overflow");
                      require(_bytes.length >= _start + _length, "slice_outOfBounds");
                      bytes memory tempBytes;
                      assembly {
                          switch iszero(_length)
                          case 0 {
                              // Get a location of some free memory and store it in tempBytes as
                              // Solidity does for memory variables.
                              tempBytes := mload(0x40)
                              // The first word of the slice result is potentially a partial
                              // word read from the original array. To read it, we calculate
                              // the length of that partial word and start copying that many
                              // bytes into the array. The first word we copy will start with
                              // data we don't care about, but the last `lengthmod` bytes will
                              // land at the beginning of the contents of the new array. When
                              // we're done copying, we overwrite the full first word with
                              // the actual length of the slice.
                              let lengthmod := and(_length, 31)
                              // The multiplication in the next line is necessary
                              // because when slicing multiples of 32 bytes (lengthmod == 0)
                              // the following copy loop was copying the origin's length
                              // and then ending prematurely not copying everything it should.
                              let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                              let end := add(mc, _length)
                              for {
                                  // The multiplication in the next line has the same exact purpose
                                  // as the one above.
                                  let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                              } lt(mc, end) {
                                  mc := add(mc, 0x20)
                                  cc := add(cc, 0x20)
                              } {
                                  mstore(mc, mload(cc))
                              }
                              mstore(tempBytes, _length)
                              //update free-memory pointer
                              //allocating the array padded to 32 bytes like the compiler does now
                              mstore(0x40, and(add(mc, 31), not(31)))
                          }
                          //if we want a zero-length slice let's just return a zero-length array
                          default {
                              tempBytes := mload(0x40)
                              //zero out the 32 bytes slice we are about to return
                              //we need to do it because Solidity does not garbage collect
                              mstore(tempBytes, 0)
                              mstore(0x40, add(tempBytes, 0x20))
                          }
                      }
                      return tempBytes;
                  }
                  function slice(bytes memory _bytes, uint256 _start) internal pure returns (bytes memory) {
                      if (_start >= _bytes.length) {
                          return bytes("");
                      }
                      return slice(_bytes, _start, _bytes.length - _start);
                  }
                  function toBytes32(bytes memory _bytes) internal pure returns (bytes32) {
                      if (_bytes.length < 32) {
                          bytes32 ret;
                          assembly {
                              ret := mload(add(_bytes, 32))
                          }
                          return ret;
                      }
                      return abi.decode(_bytes, (bytes32)); // will truncate if input length > 32 bytes
                  }
                  function toUint256(bytes memory _bytes) internal pure returns (uint256) {
                      return uint256(toBytes32(_bytes));
                  }
                  function toNibbles(bytes memory _bytes) internal pure returns (bytes memory) {
                      bytes memory nibbles = new bytes(_bytes.length * 2);
                      for (uint256 i = 0; i < _bytes.length; i++) {
                          nibbles[i * 2] = _bytes[i] >> 4;
                          nibbles[i * 2 + 1] = bytes1(uint8(_bytes[i]) % 16);
                      }
                      return nibbles;
                  }
                  function fromNibbles(bytes memory _bytes) internal pure returns (bytes memory) {
                      bytes memory ret = new bytes(_bytes.length / 2);
                      for (uint256 i = 0; i < ret.length; i++) {
                          ret[i] = (_bytes[i * 2] << 4) | (_bytes[i * 2 + 1]);
                      }
                      return ret;
                  }
                  function equal(bytes memory _bytes, bytes memory _other) internal pure returns (bool) {
                      return keccak256(_bytes) == keccak256(_other);
                  }
              }
              // SPDX-License-Identifier: Apache-2.0
              /*
               * Copyright 2019-2021, Offchain Labs, Inc.
               *
               * 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 ^0.8.7;
              library AddressAliasHelper {
                  uint160 constant offset = uint160(0x1111000000000000000000000000000000001111);
                  /// @notice Utility function that converts the address in the L1 that submitted a tx to
                  /// the inbox to the msg.sender viewed in the L2
                  /// @param l1Address the address in the L1 that triggered the tx to L2
                  /// @return l2Address L2 address as viewed in msg.sender
                  function applyL1ToL2Alias(address l1Address) internal pure returns (address l2Address) {
                      unchecked {
                          l2Address = address(uint160(l1Address) + offset);
                      }
                  }
                  /// @notice Utility function that converts the msg.sender viewed in the L2 to the
                  /// address in the L1 that submitted a tx to the inbox
                  /// @param l2Address L2 address as viewed in msg.sender
                  /// @return l1Address the address in the L1 that triggered the tx to L2
                  function undoL1ToL2Alias(address l2Address) internal pure returns (address l1Address) {
                      unchecked {
                          l1Address = address(uint160(l2Address) - offset);
                      }
                  }
              }