ETH Price: $1,861.30 (-0.62%)

Transaction Decoder

Block:
18601503 at Nov-18-2023 09:50:11 PM +UTC
Transaction Fee:
0.004946932801316385 ETH $9.21
Gas Used:
307,023 Gas / 16.112580495 Gwei

Emitted Events:

402 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000009c9411ec47a85dea243fb605e1743ccd702d408a, 0x00000000000000000000000086355f02119bdbc28ed6a4d5e0ca327ca7730fff, 000000000000000000000000000000000000000000000000000000000beb73e0 )
403 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000009c9411ec47a85dea243fb605e1743ccd702d408a, 0x000000000000000000000000b4cb3d27dba4392d507a3c266de32b04dd9e0b06, 0000000000000000000000000000000000000000000000000000000000004e20 )
404 OFTWrapper.WrapperFees( partnerId=System.Byte[], token=FiatTokenProxy, wrapperFee=40000, callerFee=20000 )
405 FiatTokenProxy.0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925( 0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925, 0x00000000000000000000000086355f02119bdbc28ed6a4d5e0ca327ca7730fff, 0x00000000000000000000000028a92dde19d9989f39a49905d7c9c2fac7799bdf, 000000000000000000000000000000000000000000000000000000000bead7a0 )
406 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x00000000000000000000000086355f02119bdbc28ed6a4d5e0ca327ca7730fff, 0x00000000000000000000000028a92dde19d9989f39a49905d7c9c2fac7799bdf, 000000000000000000000000000000000000000000000000000000000bead7a0 )
407 OptimizedTransparentUpgradeableProxy.0xdf21c415b78ed2552cc9971249e32a053abce6087a0ae0fbf3f78db5174a3493( 0xdf21c415b78ed2552cc9971249e32a053abce6087a0ae0fbf3f78db5174a3493, 0000000000000000000000000000000000000000000000000001a73d3c01cea7 )
408 UltraLightNodeV2.RelayerParams( adapterParams=0x000100000000000000000000000000000000000000000000000000000000000186A0, outboundProofType=1 )
409 VerifierNetwork.VerifierFeePaid( fee=563266661559 )
410 UltraLightNodeV2.Packet( payload=0x0000000000000654006528A92DDE19D9989F39A49905D7C9C2FAC7799BDF007028A92DDE19D9989F39A49905D7C9C2FAC7799BDF000000000000000000000000009C9411EC47A85DEA243FB605E1743CCD702D408A000000000BEAD7A0 )
411 USDCProxyOFTV2.SendToChain( _dstChainId=112, _from=[Receiver] OFTWrapper, _toAddress=0000000000000000000000009C9411EC47A85DEA243FB605E1743CCD702D408A, _amount=199940000 )

Account State Difference:

  Address   Before After State Difference Code
2.330862419491563018 Eth2.330893121791563018 Eth0.0000307023
0x28a92dde...Ac7799bDf
0x4D73AdB7...401A178E2
(Layer Zero: Ultra Light Node v2)
6.666267136197942703 Eth6.666733055882909965 Eth0.000465919684967262
0x5B905fE0...FAbf76068
(LayerZero: Nonce)
0x66A71Dce...C225Cd675
(LayerZero: Ethereum Endpoint)
0x9C9411Ec...D702d408A
1.217899879072600161 Eth
Nonce: 763
1.212487026586316514 Eth
Nonce: 764
0.005412852486283647
0xA0b86991...E3606eB48

Execution Trace

ETH 0.000465919684967262 OFTWrapper.sendProxyOFTV2( _proxyOft=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf, _dstChainId=112, _toAddress=0000000000000000000000009C9411EC47A85DEA243FB605E1743CCD702D408A, _amount=200000000, _minAmount=199000000, _callParams=[{name:refundAddress, type:address, order:1, indexed:false, value:0x9C9411Ec47a85DEA243FB605e1743CcD702d408A, valueString:0x9C9411Ec47a85DEA243FB605e1743CcD702d408A}, {name:zroPaymentAddress, type:address, order:2, indexed:false, value:0x0000000000000000000000000000000000000000, valueString:0x0000000000000000000000000000000000000000}, {name:adapterParams, type:bytes, order:3, indexed:false, value:0x000100000000000000000000000000000000000000000000000000000000000186A0, valueString:0x000100000000000000000000000000000000000000000000000000000000000186A0}], _feeObj=[{name:callerBps, type:uint256, order:1, indexed:false, value:1, valueString:1}, {name:caller, type:address, order:2, indexed:false, value:0xb4CB3d27dbA4392D507A3c266de32b04dD9e0B06, valueString:0xb4CB3d27dbA4392D507A3c266de32b04dD9e0B06}, {name:partnerId, type:bytes2, order:3, indexed:false, value:ACI=, valueString:System.Byte[]}] )
  • USDCProxyOFTV2.STATICCALL( )
  • FiatTokenProxy.23b872dd( )
    • FiatTokenV2_1.transferFrom( from=0x9C9411Ec47a85DEA243FB605e1743CcD702d408A, to=0x86355F02119bdBC28ED6A4D5E0cA327Ca7730fFF, value=199980000 ) => ( True )
    • FiatTokenProxy.23b872dd( )
      • FiatTokenV2_1.transferFrom( from=0x9C9411Ec47a85DEA243FB605e1743CcD702d408A, to=0xb4CB3d27dbA4392D507A3c266de32b04dD9e0B06, value=20000 ) => ( True )
      • FiatTokenProxy.dd62ed3e( )
        • FiatTokenV2_1.allowance( owner=0x86355F02119bdBC28ED6A4D5E0cA327Ca7730fFF, spender=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf ) => ( 0 )
        • FiatTokenProxy.095ea7b3( )
          • FiatTokenV2_1.approve( spender=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf, value=199940000 ) => ( True )
          • ETH 0.000465919684967262 USDCProxyOFTV2.sendFrom( _from=0x86355F02119bdBC28ED6A4D5E0cA327Ca7730fFF, _dstChainId=112, _toAddress=0000000000000000000000009C9411EC47A85DEA243FB605E1743CCD702D408A, _amount=199940000, _callParams=[{name:refundAddress, type:address, order:1, indexed:false, value:0x9C9411Ec47a85DEA243FB605e1743CcD702d408A, valueString:0x9C9411Ec47a85DEA243FB605e1743CcD702d408A}, {name:zroPaymentAddress, type:address, order:2, indexed:false, value:0x0000000000000000000000000000000000000000, valueString:0x0000000000000000000000000000000000000000}, {name:adapterParams, type:bytes, order:3, indexed:false, value:0x000100000000000000000000000000000000000000000000000000000000000186A0, valueString:0x000100000000000000000000000000000000000000000000000000000000000186A0}] )
            • FiatTokenProxy.70a08231( )
              • FiatTokenV2_1.balanceOf( account=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf ) => ( 9817763938379 )
              • FiatTokenProxy.23b872dd( )
                • FiatTokenV2_1.transferFrom( from=0x86355F02119bdBC28ED6A4D5E0cA327Ca7730fFF, to=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf, value=199940000 ) => ( True )
                • FiatTokenProxy.70a08231( )
                  • FiatTokenV2_1.balanceOf( account=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf ) => ( 9817963878379 )
                  • ETH 0.000465919684967262 Endpoint.send( _dstChainId=112, _destination=0x28A92DDE19D9989F39A49905D7C9C2FAC7799BDF28A92DDE19D9989F39A49905D7C9C2FAC7799BDF, _payload=0x000000000000000000000000009C9411EC47A85DEA243FB605E1743CCD702D408A000000000BEAD7A0, _refundAddress=0x9C9411Ec47a85DEA243FB605e1743CcD702d408A, _zroPaymentAddress=0x0000000000000000000000000000000000000000, _adapterParams=0x000100000000000000000000000000000000000000000000000000000000000186A0 )
                    • ETH 0.000465919684967262 UltraLightNodeV2.send( _ua=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf, 1620, _dstChainId=112, _path=0x28A92DDE19D9989F39A49905D7C9C2FAC7799BDF28A92DDE19D9989F39A49905D7C9C2FAC7799BDF, _payload=0x000000000000000000000000009C9411EC47A85DEA243FB605E1743CCD702D408A000000000BEAD7A0, _refundAddress=0x9C9411Ec47a85DEA243FB605e1743CcD702d408A, _zroPaymentAddress=0x0000000000000000000000000000000000000000, _adapterParams=0x000100000000000000000000000000000000000000000000000000000000000186A0 )
                      • NonceContract.increment( _chainId=112, _ua=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf, _path=0x28A92DDE19D9989F39A49905D7C9C2FAC7799BDF28A92DDE19D9989F39A49905D7C9C2FAC7799BDF ) => ( 1620 )
                        • Endpoint.getSendLibraryAddress( _userApplication=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf ) => ( sendLibraryAddress=0x4D73AdB72bC3DD368966edD0f0b2148401A178E2 )
                        • OptimizedTransparentUpgradeableProxy.5886ea65( )
                          • 0xb830a5afcbebb936c30c607a18bbba9f5b0a592f.5886ea65( )
                            • OptimizedTransparentUpgradeableProxy.88a4124c( )
                            • VerifierNetwork.assignJob( _dstEid=112, 1, _confirmations=15, _sender=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf ) => ( totalFee=563266661559 )
                              • VerifierFeeLib.getFeeOnSend( _params=[{name:priceFeed, type:address, order:1, indexed:false, value:0xC03f31fD86a9077785b7bCf6598Ce3598Fa91113, valueString:0xC03f31fD86a9077785b7bCf6598Ce3598Fa91113}, {name:dstEid, type:uint32, order:2, indexed:false, value:112, valueString:112}, {name:confirmations, type:uint64, order:3, indexed:false, value:15, valueString:15}, {name:sender, type:address, order:4, indexed:false, value:0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf, valueString:0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf}, {name:quorum, type:uint64, order:5, indexed:false, value:2, valueString:2}, {name:defaultMultiplierBps, type:uint16, order:6, indexed:false, value:12000, valueString:12000}], _dstConfig=[{name:gas, type:uint64, order:1, indexed:false, value:77000, valueString:77000}, {name:multiplierBps, type:uint16, order:2, indexed:false, value:12000, valueString:12000}, {name:floorMarginUSD, type:uint128, order:3, indexed:false, value:0, valueString:0}], 0x ) => ( 563266661559 )
                                • OptimizedTransparentUpgradeableProxy.c1723a1d( )
                                • TreasuryV2.getFees( payInZro=False, relayerFee=465356418305703, oracleFee=563266661559 ) => ( 0 )
                                • FiatTokenProxy.dd62ed3e( )
                                  • FiatTokenV2_1.allowance( owner=0x86355F02119bdBC28ED6A4D5E0cA327Ca7730fFF, spender=0x28a92dde19D9989F39A49905d7C9C2FAc7799bDf ) => ( 0 )
                                    File 1 of 12: OFTWrapper
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.8.0;
                                    import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
                                    import "@openzeppelin/contracts/access/Ownable.sol";
                                    import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
                                    import "@layerzerolabs/solidity-examples/contracts/token/oft/v2/IOFTV2.sol";
                                    import "@layerzerolabs/solidity-examples/contracts/token/oft/v2/fee/IOFTWithFee.sol";
                                    import "@layerzerolabs/solidity-examples/contracts/token/oft/IOFT.sol";
                                    import "./interfaces/IOFTWrapper.sol";
                                    contract OFTWrapper is IOFTWrapper, Ownable, ReentrancyGuard {
                                        using SafeERC20 for IOFT;
                                        uint256 public constant BPS_DENOMINATOR = 10000;
                                        uint256 public constant MAX_UINT = 2**256 - 1; // indicates a bp fee of 0 that overrides the default bps
                                        uint256 public defaultBps;
                                        mapping(address => uint256) public oftBps;
                                        constructor(uint256 _defaultBps) {
                                            require(_defaultBps < BPS_DENOMINATOR, "OFTWrapper: defaultBps >= 100%");
                                            defaultBps = _defaultBps;
                                        }
                                        function setDefaultBps(uint256 _defaultBps) external onlyOwner {
                                            require(_defaultBps < BPS_DENOMINATOR, "OFTWrapper: defaultBps >= 100%");
                                            defaultBps = _defaultBps;
                                        }
                                        function setOFTBps(address _token, uint256 _bps) external onlyOwner {
                                            require(_bps < BPS_DENOMINATOR || _bps == MAX_UINT, "OFTWrapper: oftBps[_oft] >= 100%");
                                            oftBps[_token] = _bps;
                                        }
                                        function withdrawFees(
                                            address _oft,
                                            address _to,
                                            uint256 _amount
                                        ) external onlyOwner {
                                            IOFT(_oft).safeTransfer(_to, _amount);
                                            emit WrapperFeeWithdrawn(_oft, _to, _amount);
                                        }
                                        function sendOFT(
                                            address _oft,
                                            uint16 _dstChainId,
                                            bytes calldata _toAddress,
                                            uint256 _amount,
                                            uint256 _minAmount,
                                            address payable _refundAddress,
                                            address _zroPaymentAddress,
                                            bytes calldata _adapterParams,
                                            FeeObj calldata _feeObj
                                        ) external payable nonReentrant {
                                            uint256 amountToSwap = _getAmountAndPayFee(_oft, _amount, _minAmount, _feeObj);
                                            IOFT(_oft).sendFrom{value: msg.value}(msg.sender, _dstChainId, _toAddress, amountToSwap, _refundAddress, _zroPaymentAddress, _adapterParams);
                                        }
                                        function sendProxyOFT(
                                            address _proxyOft,
                                            uint16 _dstChainId,
                                            bytes calldata _toAddress,
                                            uint256 _amount,
                                            uint256 _minAmount,
                                            address payable _refundAddress,
                                            address _zroPaymentAddress,
                                            bytes calldata _adapterParams,
                                            FeeObj calldata _feeObj
                                        ) external payable nonReentrant {
                                            address token = IOFTV2(_proxyOft).token();
                                            {
                                                uint256 amountToSwap = _getAmountAndPayFeeProxy(token, _amount, _minAmount, _feeObj);
                                                // approve proxy to spend tokens
                                                IOFT(token).safeApprove(_proxyOft, amountToSwap);
                                                IOFT(_proxyOft).sendFrom{value: msg.value}(address(this), _dstChainId, _toAddress, amountToSwap, _refundAddress, _zroPaymentAddress, _adapterParams);
                                            }
                                            // reset allowance if sendFrom() does not consume full amount
                                            if (IOFT(token).allowance(address(this), _proxyOft) > 0) IOFT(token).safeApprove(_proxyOft, 0);
                                        }
                                        function sendOFTV2(
                                            address _oft,
                                            uint16 _dstChainId,
                                            bytes32 _toAddress,
                                            uint256 _amount,
                                            uint256 _minAmount,
                                            IOFTV2.LzCallParams calldata _callParams,
                                            FeeObj calldata _feeObj
                                        ) external payable nonReentrant {
                                            uint256 amountToSwap = _getAmountAndPayFee(_oft, _amount, _minAmount, _feeObj);
                                            IOFTV2(_oft).sendFrom{value: msg.value}(msg.sender, _dstChainId, _toAddress, amountToSwap, _callParams);
                                        }
                                        function sendOFTFeeV2(
                                            address _oft,
                                            uint16 _dstChainId,
                                            bytes32 _toAddress,
                                            uint256 _amount,
                                            uint256 _minAmount,
                                            IOFTV2.LzCallParams calldata _callParams,
                                            FeeObj calldata _feeObj
                                        ) external payable nonReentrant {
                                            uint256 amountToSwap = _getAmountAndPayFee(_oft, _amount, _minAmount, _feeObj);
                                            IOFTWithFee(_oft).sendFrom{value: msg.value}(msg.sender, _dstChainId, _toAddress, amountToSwap, _minAmount, _callParams);
                                        }
                                        function sendProxyOFTV2(
                                            address _proxyOft,
                                            uint16 _dstChainId,
                                            bytes32 _toAddress,
                                            uint256 _amount,
                                            uint256 _minAmount,
                                            IOFTV2.LzCallParams calldata _callParams,
                                            FeeObj calldata _feeObj
                                        ) external payable nonReentrant {
                                            address token = IOFTV2(_proxyOft).token();
                                            uint256 amountToSwap = _getAmountAndPayFeeProxy(token, _amount, _minAmount, _feeObj);
                                            // approve proxy to spend tokens
                                            IOFT(token).safeApprove(_proxyOft, amountToSwap);
                                            IOFTV2(_proxyOft).sendFrom{value: msg.value}(address(this), _dstChainId, _toAddress, amountToSwap, _callParams);
                                            // reset allowance if sendFrom() does not consume full amount
                                            if (IOFT(token).allowance(address(this), _proxyOft) > 0) IOFT(token).safeApprove(_proxyOft, 0);
                                        }
                                        function sendProxyOFTFeeV2(
                                            address _proxyOft,
                                            uint16 _dstChainId,
                                            bytes32 _toAddress,
                                            uint256 _amount,
                                            uint256 _minAmount,
                                            IOFTV2.LzCallParams calldata _callParams,
                                            FeeObj calldata _feeObj
                                        ) external payable nonReentrant {
                                            address token = IOFTV2(_proxyOft).token();
                                            uint256 amountToSwap = _getAmountAndPayFeeProxy(token, _amount, _minAmount, _feeObj);
                                            // approve proxy to spend tokens
                                            IOFT(token).safeApprove(_proxyOft, amountToSwap);
                                            IOFTWithFee(_proxyOft).sendFrom{value: msg.value}(address(this), _dstChainId, _toAddress, amountToSwap, _minAmount, _callParams);
                                            // reset allowance if sendFrom() does not consume full amount
                                            if (IOFT(token).allowance(address(this), _proxyOft) > 0) IOFT(token).safeApprove(_proxyOft, 0);
                                        }
                                        function _getAmountAndPayFeeProxy(
                                            address _token,
                                            uint256 _amount,
                                            uint256 _minAmount,
                                            FeeObj calldata _feeObj
                                        ) internal returns (uint256) {
                                            (uint256 amountToSwap, uint256 wrapperFee, uint256 callerFee) = getAmountAndFees(_token, _amount, _feeObj.callerBps);
                                            require(amountToSwap >= _minAmount && amountToSwap > 0, "OFTWrapper: not enough amountToSwap");
                                            IOFT(_token).safeTransferFrom(msg.sender, address(this), amountToSwap + wrapperFee); // pay wrapper and move proxy tokens to contract
                                            if (callerFee > 0) IOFT(_token).safeTransferFrom(msg.sender, _feeObj.caller, callerFee); // pay caller
                                            emit WrapperFees(_feeObj.partnerId, _token, wrapperFee, callerFee);
                                            return amountToSwap;
                                        }
                                        function _getAmountAndPayFee(
                                            address _token,
                                            uint256 _amount,
                                            uint256 _minAmount,
                                            FeeObj calldata _feeObj
                                        ) internal returns (uint256) {
                                            (uint256 amountToSwap, uint256 wrapperFee, uint256 callerFee) = getAmountAndFees(_token, _amount, _feeObj.callerBps);
                                            require(amountToSwap >= _minAmount && amountToSwap > 0, "OFTWrapper: not enough amountToSwap");
                                            if (wrapperFee > 0) IOFT(_token).safeTransferFrom(msg.sender, address(this), wrapperFee); // pay wrapper
                                            if (callerFee > 0) IOFT(_token).safeTransferFrom(msg.sender, _feeObj.caller, callerFee); // pay caller
                                            emit WrapperFees(_feeObj.partnerId, _token, wrapperFee, callerFee);
                                            return amountToSwap;
                                        }
                                        function getAmountAndFees(
                                            address _token, // will be the token on proxies, and the oft on non-proxy
                                            uint256 _amount,
                                            uint256 _callerBps
                                        )
                                            public
                                            view
                                            override
                                            returns (
                                                uint256 amount,
                                                uint256 wrapperFee,
                                                uint256 callerFee
                                            )
                                        {
                                            uint256 wrapperBps;
                                            if (oftBps[_token] == MAX_UINT) {
                                                wrapperBps = 0;
                                            } else if (oftBps[_token] > 0) {
                                                wrapperBps = oftBps[_token];
                                            } else {
                                                wrapperBps = defaultBps;
                                            }
                                            require(wrapperBps + _callerBps < BPS_DENOMINATOR, "OFTWrapper: Fee bps >= 100%");
                                            wrapperFee = wrapperBps > 0 ? (_amount * wrapperBps) / BPS_DENOMINATOR : 0;
                                            callerFee = _callerBps > 0 ? (_amount * _callerBps) / BPS_DENOMINATOR : 0;
                                            amount = wrapperFee > 0 || callerFee > 0 ? _amount - wrapperFee - callerFee : _amount;
                                        }
                                        function estimateSendFee(
                                            address _oft,
                                            uint16 _dstChainId,
                                            bytes calldata _toAddress,
                                            uint256 _amount,
                                            bool _useZro,
                                            bytes calldata _adapterParams,
                                            FeeObj calldata _feeObj
                                        ) external view override returns (uint nativeFee, uint zroFee) {
                                            (uint256 amount, , ) = getAmountAndFees(_oft, _amount, _feeObj.callerBps);
                                            return IOFT(_oft).estimateSendFee(_dstChainId, _toAddress, amount, _useZro, _adapterParams);
                                        }
                                        function estimateSendFeeV2(
                                            address _oft,
                                            uint16 _dstChainId,
                                            bytes32 _toAddress,
                                            uint256 _amount,
                                            bool _useZro,
                                            bytes calldata _adapterParams,
                                            FeeObj calldata _feeObj
                                        ) external view override returns (uint nativeFee, uint zroFee) {
                                            (uint256 amount, , ) = getAmountAndFees(_oft, _amount, _feeObj.callerBps);
                                            return IOFTV2(_oft).estimateSendFee(_dstChainId, _toAddress, amount, _useZro, _adapterParams);
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev Interface of the ERC165 standard, as defined in the
                                     * https://eips.ethereum.org/EIPS/eip-165[EIP].
                                     *
                                     * Implementers can declare support of contract interfaces, which can then be
                                     * queried by others ({ERC165Checker}).
                                     *
                                     * For an implementation, see {ERC165}.
                                     */
                                    interface IERC165 {
                                        /**
                                         * @dev Returns true if this contract implements the interface defined by
                                         * `interfaceId`. See the corresponding
                                         * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                                         * to learn more about how these ids are created.
                                         *
                                         * This function call must use less than 30 000 gas.
                                         */
                                        function supportsInterface(bytes4 interfaceId) external view returns (bool);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity >=0.5.0;
                                    import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
                                    /**
                                     * @dev Interface of the IOFT core standard
                                     */
                                    interface IOFTCore is IERC165 {
                                        /**
                                         * @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
                                         * _dstChainId - L0 defined chain id to send tokens too
                                         * _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
                                         * _amount - amount of the tokens to transfer
                                         * _useZro - indicates to use zro to pay L0 fees
                                         * _adapterParam - flexible bytes array to indicate messaging adapter services in L0
                                         */
                                        function estimateSendFee(uint16 _dstChainId, bytes calldata _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);
                                        /**
                                         * @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
                                         * `_from` the owner of token
                                         * `_dstChainId` the destination chain identifier
                                         * `_toAddress` can be any size depending on the `dstChainId`.
                                         * `_amount` the quantity of tokens in wei
                                         * `_refundAddress` the address LayerZero refunds if too much message fee is sent
                                         * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
                                         * `_adapterParams` is a flexible bytes array to indicate messaging adapter services
                                         */
                                        function sendFrom(address _from, uint16 _dstChainId, bytes calldata _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
                                        /**
                                         * @dev returns the circulating amount of tokens on current chain
                                         */
                                        function circulatingSupply() external view returns (uint);
                                        /**
                                         * @dev returns the address of the ERC20 token
                                         */
                                        function token() external view returns (address);
                                        /**
                                         * @dev Emitted when `_amount` tokens are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
                                         * `_nonce` is the outbound nonce
                                         */
                                        event SendToChain(uint16 indexed _dstChainId, address indexed _from, bytes _toAddress, uint _amount);
                                        /**
                                         * @dev Emitted when `_amount` tokens are received from `_srcChainId` into the `_toAddress` on the local chain.
                                         * `_nonce` is the inbound nonce.
                                         */
                                        event ReceiveFromChain(uint16 indexed _srcChainId, address indexed _to, uint _amount);
                                        event SetUseCustomAdapterParams(bool _useCustomAdapterParams);
                                    }
                                    // 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
                                    pragma solidity >=0.5.0;
                                    import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
                                    /**
                                     * @dev Interface of the IOFT core standard
                                     */
                                    interface ICommonOFT is IERC165 {
                                        struct LzCallParams {
                                            address payable refundAddress;
                                            address zroPaymentAddress;
                                            bytes adapterParams;
                                        }
                                        /**
                                         * @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
                                         * _dstChainId - L0 defined chain id to send tokens too
                                         * _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
                                         * _amount - amount of the tokens to transfer
                                         * _useZro - indicates to use zro to pay L0 fees
                                         * _adapterParam - flexible bytes array to indicate messaging adapter services in L0
                                         */
                                        function estimateSendFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);
                                        function estimateSendAndCallFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);
                                        /**
                                         * @dev returns the circulating amount of tokens on current chain
                                         */
                                        function circulatingSupply() external view returns (uint);
                                        /**
                                         * @dev returns the address of the ERC20 token
                                         */
                                        function token() external view returns (address);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
                                     * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
                                     *
                                     * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
                                     * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
                                     * need to send a transaction, and thus is not required to hold Ether at all.
                                     */
                                    interface IERC20Permit {
                                        /**
                                         * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
                                         * given ``owner``'s signed approval.
                                         *
                                         * IMPORTANT: The same issues {IERC20-approve} has related to transaction
                                         * ordering also apply here.
                                         *
                                         * Emits an {Approval} event.
                                         *
                                         * Requirements:
                                         *
                                         * - `spender` cannot be the zero address.
                                         * - `deadline` must be a timestamp in the future.
                                         * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
                                         * over the EIP712-formatted function arguments.
                                         * - the signature must use ``owner``'s current nonce (see {nonces}).
                                         *
                                         * For more information on the signature format, see the
                                         * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
                                         * section].
                                         */
                                        function permit(
                                            address owner,
                                            address spender,
                                            uint256 value,
                                            uint256 deadline,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) external;
                                        /**
                                         * @dev Returns the current nonce for `owner`. This value must be
                                         * included whenever a signature is generated for {permit}.
                                         *
                                         * Every successful call to {permit} increases ``owner``'s nonce by one. This
                                         * prevents a signature from being used multiple times.
                                         */
                                        function nonces(address owner) external view returns (uint256);
                                        /**
                                         * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
                                         */
                                        // solhint-disable-next-line func-name-mixedcase
                                        function DOMAIN_SEPARATOR() external view returns (bytes32);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.8.0) (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 functionCallWithValue(target, data, 0, "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");
                                            (bool success, bytes memory returndata) = target.call{value: value}(data);
                                            return verifyCallResultFromTarget(target, 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) {
                                            (bool success, bytes memory returndata) = target.staticcall(data);
                                            return verifyCallResultFromTarget(target, 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) {
                                            (bool success, bytes memory returndata) = target.delegatecall(data);
                                            return verifyCallResultFromTarget(target, success, returndata, errorMessage);
                                        }
                                        /**
                                         * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
                                         * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
                                         *
                                         * _Available since v4.8._
                                         */
                                        function verifyCallResultFromTarget(
                                            address target,
                                            bool success,
                                            bytes memory returndata,
                                            string memory errorMessage
                                        ) internal view returns (bytes memory) {
                                            if (success) {
                                                if (returndata.length == 0) {
                                                    // only check isContract if the call was successful and the return data is empty
                                                    // otherwise we already know that it was a contract
                                                    require(isContract(target), "Address: call to non-contract");
                                                }
                                                return returndata;
                                            } else {
                                                _revert(returndata, errorMessage);
                                            }
                                        }
                                        /**
                                         * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
                                         * revert reason or 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 {
                                                _revert(returndata, errorMessage);
                                            }
                                        }
                                        function _revert(bytes memory returndata, string memory errorMessage) private pure {
                                            // Look for revert reason and bubble it up if present
                                            if (returndata.length > 0) {
                                                // The easiest way to bubble the revert reason is using memory via assembly
                                                /// @solidity memory-safe-assembly
                                                assembly {
                                                    let returndata_size := mload(returndata)
                                                    revert(add(32, returndata), returndata_size)
                                                }
                                            } else {
                                                revert(errorMessage);
                                            }
                                        }
                                    }
                                    // 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;
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.8.0) (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() {
                                            _nonReentrantBefore();
                                            _;
                                            _nonReentrantAfter();
                                        }
                                        function _nonReentrantBefore() private {
                                            // On the first call to nonReentrant, _status will be _NOT_ENTERED
                                            require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                                            // Any calls to nonReentrant after this point will fail
                                            _status = _ENTERED;
                                        }
                                        function _nonReentrantAfter() private {
                                            // 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
                                    // OpenZeppelin Contracts (last updated v4.7.0) (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 Throws if called by any account other than the owner.
                                         */
                                        modifier onlyOwner() {
                                            _checkOwner();
                                            _;
                                        }
                                        /**
                                         * @dev Returns the address of the current owner.
                                         */
                                        function owner() public view virtual returns (address) {
                                            return _owner;
                                        }
                                        /**
                                         * @dev Throws if the sender is not the owner.
                                         */
                                        function _checkOwner() internal view virtual {
                                            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 (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)
                                    pragma solidity ^0.8.0;
                                    import "../IERC20.sol";
                                    import "../extensions/draft-IERC20Permit.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));
                                            }
                                        }
                                        function safePermit(
                                            IERC20Permit token,
                                            address owner,
                                            address spender,
                                            uint256 value,
                                            uint256 deadline,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) internal {
                                            uint256 nonceBefore = token.nonces(owner);
                                            token.permit(owner, spender, value, deadline, v, r, s);
                                            uint256 nonceAfter = token.nonces(owner);
                                            require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
                                        }
                                        /**
                                         * @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
                                    pragma solidity >=0.5.0;
                                    import "./ICommonOFT.sol";
                                    /**
                                     * @dev Interface of the IOFT core standard
                                     */
                                    interface IOFTV2 is ICommonOFT {
                                        /**
                                         * @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
                                         * `_from` the owner of token
                                         * `_dstChainId` the destination chain identifier
                                         * `_toAddress` can be any size depending on the `dstChainId`.
                                         * `_amount` the quantity of tokens in wei
                                         * `_refundAddress` the address LayerZero refunds if too much message fee is sent
                                         * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
                                         * `_adapterParams` is a flexible bytes array to indicate messaging adapter services
                                         */
                                        function sendFrom(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, LzCallParams calldata _callParams) external payable;
                                        function sendAndCall(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, LzCallParams calldata _callParams) external payable;
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity >=0.5.0;
                                    import "../ICommonOFT.sol";
                                    /**
                                     * @dev Interface of the IOFT core standard
                                     */
                                    interface IOFTWithFee is ICommonOFT {
                                        /**
                                         * @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
                                         * `_from` the owner of token
                                         * `_dstChainId` the destination chain identifier
                                         * `_toAddress` can be any size depending on the `dstChainId`.
                                         * `_amount` the quantity of tokens in wei
                                         * `_minAmount` the minimum amount of tokens to receive on dstChain
                                         * `_refundAddress` the address LayerZero refunds if too much message fee is sent
                                         * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
                                         * `_adapterParams` is a flexible bytes array to indicate messaging adapter services
                                         */
                                        function sendFrom(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, uint _minAmount, LzCallParams calldata _callParams) external payable;
                                        function sendAndCall(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, uint _minAmount, bytes calldata _payload, uint64 _dstGasForCall, LzCallParams calldata _callParams) external payable;
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity >=0.5.0;
                                    import "./IOFTCore.sol";
                                    import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                                    /**
                                     * @dev Interface of the OFT standard
                                     */
                                    interface IOFT is IOFTCore, IERC20 {
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.8.0;
                                    import "@layerzerolabs/solidity-examples/contracts/token/oft/v2/IOFTV2.sol";
                                    interface IOFTWrapper {
                                        event WrapperFees(bytes2 indexed partnerId, address token, uint256 wrapperFee, uint256 callerFee);
                                        event WrapperFeeWithdrawn(address indexed oft, address to, uint256 amount);
                                        struct FeeObj {
                                            uint256 callerBps;
                                            address caller;
                                            bytes2 partnerId;
                                        }
                                        function sendOFT(
                                            address _oft,
                                            uint16 _dstChainId,
                                            bytes calldata _toAddress,
                                            uint _amount,
                                            uint256 _minAmount,
                                            address payable _refundAddress,
                                            address _zroPaymentAddress,
                                            bytes calldata _adapterParams,
                                            FeeObj calldata _feeObj
                                        ) external payable;
                                        function sendOFTV2(
                                            address _oft,
                                            uint16 _dstChainId,
                                            bytes32 _toAddress,
                                            uint _amount,
                                            uint256 _minAmount,
                                            IOFTV2.LzCallParams calldata _callParams,
                                            FeeObj calldata _feeObj
                                        ) external payable;
                                        function sendProxyOFTV2(
                                            address _proxyOft,
                                            uint16 _dstChainId,
                                            bytes32 _toAddress,
                                            uint _amount,
                                            uint256 _minAmount,
                                            IOFTV2.LzCallParams calldata _callParams,
                                            FeeObj calldata _feeObj
                                        ) external payable;
                                        function sendProxyOFTFeeV2(
                                            address _proxyOft,
                                            uint16 _dstChainId,
                                            bytes32 _toAddress,
                                            uint _amount,
                                            uint256 _minAmount,
                                            IOFTV2.LzCallParams calldata _callParams,
                                            FeeObj calldata _feeObj
                                        ) external payable;
                                        function getAmountAndFees(
                                            address _oft,
                                            uint256 _amount,
                                            uint256 _callerBps
                                        )
                                            external
                                            view
                                            returns (
                                                uint256 amount,
                                                uint256 wrapperFee,
                                                uint256 callerFee
                                            );
                                        function estimateSendFee(
                                            address _oft,
                                            uint16 _dstChainId,
                                            bytes calldata _toAddress,
                                            uint _amount,
                                            bool _useZro,
                                            bytes calldata _adapterParams,
                                            FeeObj calldata _feeObj
                                        ) external view returns (uint nativeFee, uint zroFee);
                                        function estimateSendFeeV2(
                                            address _oft,
                                            uint16 _dstChainId,
                                            bytes32 _toAddress,
                                            uint _amount,
                                            bool _useZro,
                                            bytes calldata _adapterParams,
                                            FeeObj calldata _feeObj
                                        ) external view returns (uint nativeFee, uint zroFee);
                                    }
                                    

                                    File 2 of 12: FiatTokenProxy
                                    pragma solidity ^0.4.24;
                                    
                                    // File: zos-lib/contracts/upgradeability/Proxy.sol
                                    
                                    /**
                                     * @title Proxy
                                     * @dev Implements delegation of calls to other contracts, with proper
                                     * forwarding of return values and bubbling of failures.
                                     * It defines a fallback function that delegates all calls to the address
                                     * returned by the abstract _implementation() internal function.
                                     */
                                    contract Proxy {
                                      /**
                                       * @dev Fallback function.
                                       * Implemented entirely in `_fallback`.
                                       */
                                      function () payable external {
                                        _fallback();
                                      }
                                    
                                      /**
                                       * @return The Address of the implementation.
                                       */
                                      function _implementation() internal view returns (address);
                                    
                                      /**
                                       * @dev Delegates execution to an implementation contract.
                                       * This is a low level function that doesn't return to its internal call site.
                                       * It will return to the external caller whatever the implementation returns.
                                       * @param implementation Address to delegate.
                                       */
                                      function _delegate(address implementation) internal {
                                        assembly {
                                          // Copy msg.data. We take full control of memory in this inline assembly
                                          // block because it will not return to Solidity code. We overwrite the
                                          // Solidity scratch pad at memory position 0.
                                          calldatacopy(0, 0, calldatasize)
                                    
                                          // Call the implementation.
                                          // out and outsize are 0 because we don't know the size yet.
                                          let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
                                    
                                          // Copy the returned data.
                                          returndatacopy(0, 0, returndatasize)
                                    
                                          switch result
                                          // delegatecall returns 0 on error.
                                          case 0 { revert(0, returndatasize) }
                                          default { return(0, returndatasize) }
                                        }
                                      }
                                    
                                      /**
                                       * @dev Function that is run as the first thing in the fallback function.
                                       * Can be redefined in derived contracts to add functionality.
                                       * Redefinitions must call super._willFallback().
                                       */
                                      function _willFallback() internal {
                                      }
                                    
                                      /**
                                       * @dev fallback implementation.
                                       * Extracted to enable manual triggering.
                                       */
                                      function _fallback() internal {
                                        _willFallback();
                                        _delegate(_implementation());
                                      }
                                    }
                                    
                                    // File: openzeppelin-solidity/contracts/AddressUtils.sol
                                    
                                    /**
                                     * Utility library of inline functions on addresses
                                     */
                                    library AddressUtils {
                                    
                                      /**
                                       * Returns whether the target address is a contract
                                       * @dev This function will return false if invoked during the constructor of a contract,
                                       * as the code is not actually created until after the constructor finishes.
                                       * @param addr address to check
                                       * @return whether the target address is a contract
                                       */
                                      function isContract(address addr) internal view returns (bool) {
                                        uint256 size;
                                        // XXX Currently there is no better way to check if there is a contract in an address
                                        // than to check the size of the code at that address.
                                        // See https://ethereum.stackexchange.com/a/14016/36603
                                        // for more details about how this works.
                                        // TODO Check this again before the Serenity release, because all addresses will be
                                        // contracts then.
                                        // solium-disable-next-line security/no-inline-assembly
                                        assembly { size := extcodesize(addr) }
                                        return size > 0;
                                      }
                                    
                                    }
                                    
                                    // File: zos-lib/contracts/upgradeability/UpgradeabilityProxy.sol
                                    
                                    /**
                                     * @title UpgradeabilityProxy
                                     * @dev This contract implements a proxy that allows to change the
                                     * implementation address to which it will delegate.
                                     * Such a change is called an implementation upgrade.
                                     */
                                    contract UpgradeabilityProxy is Proxy {
                                      /**
                                       * @dev Emitted when the implementation is upgraded.
                                       * @param implementation Address of the new implementation.
                                       */
                                      event Upgraded(address implementation);
                                    
                                      /**
                                       * @dev Storage slot with the address of the current implementation.
                                       * This is the keccak-256 hash of "org.zeppelinos.proxy.implementation", and is
                                       * validated in the constructor.
                                       */
                                      bytes32 private constant IMPLEMENTATION_SLOT = 0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3;
                                    
                                      /**
                                       * @dev Contract constructor.
                                       * @param _implementation Address of the initial implementation.
                                       */
                                      constructor(address _implementation) public {
                                        assert(IMPLEMENTATION_SLOT == keccak256("org.zeppelinos.proxy.implementation"));
                                    
                                        _setImplementation(_implementation);
                                      }
                                    
                                      /**
                                       * @dev Returns the current implementation.
                                       * @return Address of the current implementation
                                       */
                                      function _implementation() internal view returns (address impl) {
                                        bytes32 slot = IMPLEMENTATION_SLOT;
                                        assembly {
                                          impl := sload(slot)
                                        }
                                      }
                                    
                                      /**
                                       * @dev Upgrades the proxy to a new implementation.
                                       * @param newImplementation Address of the new implementation.
                                       */
                                      function _upgradeTo(address newImplementation) internal {
                                        _setImplementation(newImplementation);
                                        emit Upgraded(newImplementation);
                                      }
                                    
                                      /**
                                       * @dev Sets the implementation address of the proxy.
                                       * @param newImplementation Address of the new implementation.
                                       */
                                      function _setImplementation(address newImplementation) private {
                                        require(AddressUtils.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
                                    
                                        bytes32 slot = IMPLEMENTATION_SLOT;
                                    
                                        assembly {
                                          sstore(slot, newImplementation)
                                        }
                                      }
                                    }
                                    
                                    // File: zos-lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol
                                    
                                    /**
                                     * @title AdminUpgradeabilityProxy
                                     * @dev This contract combines an upgradeability proxy with an authorization
                                     * mechanism for administrative tasks.
                                     * All external functions in this contract must be guarded by the
                                     * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
                                     * feature proposal that would enable this to be done automatically.
                                     */
                                    contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
                                      /**
                                       * @dev Emitted when the administration has been transferred.
                                       * @param previousAdmin Address of the previous admin.
                                       * @param newAdmin Address of the new admin.
                                       */
                                      event AdminChanged(address previousAdmin, address newAdmin);
                                    
                                      /**
                                       * @dev Storage slot with the admin of the contract.
                                       * This is the keccak-256 hash of "org.zeppelinos.proxy.admin", and is
                                       * validated in the constructor.
                                       */
                                      bytes32 private constant ADMIN_SLOT = 0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b;
                                    
                                      /**
                                       * @dev Modifier to check whether the `msg.sender` is the admin.
                                       * If it is, it will run the function. Otherwise, it will delegate the call
                                       * to the implementation.
                                       */
                                      modifier ifAdmin() {
                                        if (msg.sender == _admin()) {
                                          _;
                                        } else {
                                          _fallback();
                                        }
                                      }
                                    
                                      /**
                                       * Contract constructor.
                                       * It sets the `msg.sender` as the proxy administrator.
                                       * @param _implementation address of the initial implementation.
                                       */
                                      constructor(address _implementation) UpgradeabilityProxy(_implementation) public {
                                        assert(ADMIN_SLOT == keccak256("org.zeppelinos.proxy.admin"));
                                    
                                        _setAdmin(msg.sender);
                                      }
                                    
                                      /**
                                       * @return The address of the proxy admin.
                                       */
                                      function admin() external view ifAdmin returns (address) {
                                        return _admin();
                                      }
                                    
                                      /**
                                       * @return The address of the implementation.
                                       */
                                      function implementation() external view ifAdmin returns (address) {
                                        return _implementation();
                                      }
                                    
                                      /**
                                       * @dev Changes the admin of the proxy.
                                       * Only the current admin can call this function.
                                       * @param newAdmin Address to transfer proxy administration to.
                                       */
                                      function changeAdmin(address newAdmin) external ifAdmin {
                                        require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
                                        emit AdminChanged(_admin(), newAdmin);
                                        _setAdmin(newAdmin);
                                      }
                                    
                                      /**
                                       * @dev Upgrade the backing implementation of the proxy.
                                       * Only the admin can call this function.
                                       * @param newImplementation Address of the new implementation.
                                       */
                                      function upgradeTo(address newImplementation) external ifAdmin {
                                        _upgradeTo(newImplementation);
                                      }
                                    
                                      /**
                                       * @dev Upgrade the backing implementation of the proxy and call a function
                                       * on the new implementation.
                                       * This is useful to initialize the proxied contract.
                                       * @param newImplementation Address of the new implementation.
                                       * @param data Data to send as msg.data in the low level call.
                                       * It should include the signature and the parameters of the function to be
                                       * called, as described in
                                       * https://solidity.readthedocs.io/en/develop/abi-spec.html#function-selector-and-argument-encoding.
                                       */
                                      function upgradeToAndCall(address newImplementation, bytes data) payable external ifAdmin {
                                        _upgradeTo(newImplementation);
                                        require(address(this).call.value(msg.value)(data));
                                      }
                                    
                                      /**
                                       * @return The admin slot.
                                       */
                                      function _admin() internal view returns (address adm) {
                                        bytes32 slot = ADMIN_SLOT;
                                        assembly {
                                          adm := sload(slot)
                                        }
                                      }
                                    
                                      /**
                                       * @dev Sets the address of the proxy admin.
                                       * @param newAdmin Address of the new proxy admin.
                                       */
                                      function _setAdmin(address newAdmin) internal {
                                        bytes32 slot = ADMIN_SLOT;
                                    
                                        assembly {
                                          sstore(slot, newAdmin)
                                        }
                                      }
                                    
                                      /**
                                       * @dev Only fall back when the sender is not the admin.
                                       */
                                      function _willFallback() internal {
                                        require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
                                        super._willFallback();
                                      }
                                    }
                                    
                                    // File: contracts/FiatTokenProxy.sol
                                    
                                    /**
                                    * Copyright CENTRE SECZ 2018
                                    *
                                    * Permission is hereby granted, free of charge, to any person obtaining a copy 
                                    * of this software and associated documentation files (the "Software"), to deal 
                                    * in the Software without restriction, including without limitation the rights 
                                    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
                                    * copies of the Software, and to permit persons to whom the Software is furnished to 
                                    * do so, subject to the following conditions:
                                    *
                                    * The above copyright notice and this permission notice shall be included in all 
                                    * copies or substantial portions of the Software.
                                    *
                                    * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
                                    * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
                                    * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
                                    * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
                                    * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
                                    * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
                                    */
                                    
                                    pragma solidity ^0.4.24;
                                    
                                    
                                    /**
                                     * @title FiatTokenProxy
                                     * @dev This contract proxies FiatToken calls and enables FiatToken upgrades
                                    */ 
                                    contract FiatTokenProxy is AdminUpgradeabilityProxy {
                                        constructor(address _implementation) public AdminUpgradeabilityProxy(_implementation) {
                                        }
                                    }

                                    File 3 of 12: OptimizedTransparentUpgradeableProxy
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.7.0;
                                    /**
                                     * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                                     * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                                     * be specified by overriding the virtual {_implementation} function.
                                     * 
                                     * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                                     * different contract through the {_delegate} function.
                                     * 
                                     * The success and return data of the delegated call will be returned back to the caller of the proxy.
                                     */
                                    abstract contract Proxy {
                                        /**
                                         * @dev Delegates the current call to `implementation`.
                                         * 
                                         * This function does not return to its internall call site, it will return directly to the external caller.
                                         */
                                        function _delegate(address implementation) internal {
                                            // solhint-disable-next-line no-inline-assembly
                                            assembly {
                                                // Copy msg.data. We take full control of memory in this inline assembly
                                                // block because it will not return to Solidity code. We overwrite the
                                                // Solidity scratch pad at memory position 0.
                                                calldatacopy(0, 0, calldatasize())
                                                // Call the implementation.
                                                // out and outsize are 0 because we don't know the size yet.
                                                let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                                // Copy the returned data.
                                                returndatacopy(0, 0, returndatasize())
                                                switch result
                                                // delegatecall returns 0 on error.
                                                case 0 { revert(0, returndatasize()) }
                                                default { return(0, returndatasize()) }
                                            }
                                        }
                                        /**
                                         * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
                                         * and {_fallback} should delegate.
                                         */
                                        function _implementation() internal virtual view returns (address);
                                        /**
                                         * @dev Delegates the current call to the address returned by `_implementation()`.
                                         * 
                                         * This function does not return to its internall call site, it will return directly to the external caller.
                                         */
                                        function _fallback() internal {
                                            _beforeFallback();
                                            _delegate(_implementation());
                                        }
                                        /**
                                         * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                                         * function in the contract matches the call data.
                                         */
                                        fallback () payable external {
                                            _fallback();
                                        }
                                        /**
                                         * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                                         * is empty.
                                         */
                                        receive () payable external {
                                            _fallback();
                                        }
                                        /**
                                         * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                                         * call, or as part of the Solidity `fallback` or `receive` functions.
                                         * 
                                         * If overriden should call `super._beforeFallback()`.
                                         */
                                        function _beforeFallback() internal virtual {
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.7.0;
                                    import "./Proxy.sol";
                                    import "../utils/Address.sol";
                                    /**
                                     * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
                                     * implementation address that can be changed. This address is stored in storage in the location specified by
                                     * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
                                     * implementation behind the proxy.
                                     * 
                                     * Upgradeability is only provided internally through {_upgradeTo}. For an externally upgradeable proxy see
                                     * {TransparentUpgradeableProxy}.
                                     */
                                    contract UpgradeableProxy is Proxy {
                                        /**
                                         * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                                         * 
                                         * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                                         * function call, and allows initializating the storage of the proxy like a Solidity constructor.
                                         */
                                        constructor(address _logic, bytes memory _data) payable {
                                            assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                                            _setImplementation(_logic);
                                            if(_data.length > 0) {
                                                // solhint-disable-next-line avoid-low-level-calls
                                                (bool success,) = _logic.delegatecall(_data);
                                                require(success);
                                            }
                                        }
                                        /**
                                         * @dev Emitted when the implementation is upgraded.
                                         */
                                        event Upgraded(address indexed implementation);
                                        /**
                                         * @dev Storage slot with the address of the current implementation.
                                         * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                                         * validated in the constructor.
                                         */
                                        bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                        /**
                                         * @dev Returns the current implementation address.
                                         */
                                        function _implementation() internal override view returns (address impl) {
                                            bytes32 slot = _IMPLEMENTATION_SLOT;
                                            // solhint-disable-next-line no-inline-assembly
                                            assembly {
                                                impl := sload(slot)
                                            }
                                        }
                                        /**
                                         * @dev Upgrades the proxy to a new implementation.
                                         * 
                                         * Emits an {Upgraded} event.
                                         */
                                        function _upgradeTo(address newImplementation) internal {
                                            _setImplementation(newImplementation);
                                            emit Upgraded(newImplementation);
                                        }
                                        /**
                                         * @dev Stores a new address in the EIP1967 implementation slot.
                                         */
                                        function _setImplementation(address newImplementation) private {
                                            require(Address.isContract(newImplementation), "UpgradeableProxy: new implementation is not a contract");
                                            bytes32 slot = _IMPLEMENTATION_SLOT;
                                            // solhint-disable-next-line no-inline-assembly
                                            assembly {
                                                sstore(slot, newImplementation)
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.7.0;
                                    /**
                                     * @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) {
                                            // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
                                            // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
                                            // for accounts without code, i.e. `keccak256('')`
                                            bytes32 codehash;
                                            bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
                                            // solhint-disable-next-line no-inline-assembly
                                            assembly { codehash := extcodehash(account) }
                                            return (codehash != accountHash && codehash != 0x0);
                                        }
                                        /**
                                         * @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");
                                            return _functionCallWithValue(target, data, value, errorMessage);
                                        }
                                        function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
                                            require(isContract(target), "Address: call to non-contract");
                                            // solhint-disable-next-line avoid-low-level-calls
                                            (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
                                            if (success) {
                                                return returndata;
                                            } else {
                                                // Look for revert reason and bubble it up if present
                                                if (returndata.length > 0) {
                                                    // The easiest way to bubble the revert reason is using memory via assembly
                                                    // solhint-disable-next-line no-inline-assembly
                                                    assembly {
                                                        let returndata_size := mload(returndata)
                                                        revert(add(32, returndata), returndata_size)
                                                    }
                                                } else {
                                                    revert(errorMessage);
                                                }
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.7.0;
                                    import "../openzeppelin/proxy/UpgradeableProxy.sol";
                                    /**
                                     * @dev This contract implements a proxy that is upgradeable by an admin.
                                     *
                                     * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
                                     * clashing], which can potentially be used in an attack, this contract uses the
                                     * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
                                     * things that go hand in hand:
                                     *
                                     * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
                                     * that call matches one of the admin functions exposed by the proxy itself.
                                     * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
                                     * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
                                     * "admin cannot fallback to proxy target".
                                     *
                                     * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
                                     * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
                                     * to sudden errors when trying to call a function from the proxy implementation.
                                     *
                                     * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
                                     * you should think of the `ProxyAdmin` instance as the real administrative inerface of your proxy.
                                     */
                                    contract OptimizedTransparentUpgradeableProxy is UpgradeableProxy {
                                        address internal immutable _ADMIN;
                                        /**
                                         * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
                                         * optionally initialized with `_data` as explained in {UpgradeableProxy-constructor}.
                                         */
                                        constructor(
                                            address initialLogic,
                                            address initialAdmin,
                                            bytes memory _data
                                        ) payable UpgradeableProxy(initialLogic, _data) {
                                            assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
                                            bytes32 slot = _ADMIN_SLOT;
                                            _ADMIN = initialAdmin;
                                            // still store it to work with EIP-1967
                                            // solhint-disable-next-line no-inline-assembly
                                            assembly {
                                                sstore(slot, initialAdmin)
                                            }
                                        }
                                        /**
                                         * @dev Storage slot with the admin of the contract.
                                         * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                                         * validated in the constructor.
                                         */
                                        bytes32 private constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                                        /**
                                         * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
                                         */
                                        modifier ifAdmin() {
                                            if (msg.sender == _admin()) {
                                                _;
                                            } else {
                                                _fallback();
                                            }
                                        }
                                        /**
                                         * @dev Returns the current admin.
                                         *
                                         * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
                                         *
                                         * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                                         * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                                         * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
                                         */
                                        function admin() external ifAdmin returns (address) {
                                            return _admin();
                                        }
                                        /**
                                         * @dev Returns the current implementation.
                                         *
                                         * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
                                         *
                                         * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                                         * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                                         * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
                                         */
                                        function implementation() external ifAdmin returns (address) {
                                            return _implementation();
                                        }
                                        /**
                                         * @dev Upgrade the implementation of the proxy.
                                         *
                                         * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
                                         */
                                        function upgradeTo(address newImplementation) external ifAdmin {
                                            _upgradeTo(newImplementation);
                                        }
                                        /**
                                         * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
                                         * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
                                         * proxied contract.
                                         *
                                         * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
                                         */
                                        function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
                                            _upgradeTo(newImplementation);
                                            // solhint-disable-next-line avoid-low-level-calls
                                            (bool success, ) = newImplementation.delegatecall(data);
                                            require(success);
                                        }
                                        /**
                                         * @dev Returns the current admin.
                                         */
                                        function _admin() internal view returns (address adm) {
                                            return _ADMIN;
                                        }
                                        /**
                                         * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
                                         */
                                        function _beforeFallback() internal virtual override {
                                            require(msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                                            super._beforeFallback();
                                        }
                                    }
                                    

                                    File 4 of 12: UltraLightNodeV2
                                    {"Address.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies on extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size \u003e 0;\n    }\n\n    /**\n     * @dev Replacement for Solidity\u0027s `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable to receive funds via\n     * `transfer`. {sendValue} removes this limitation.\n     *\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n     *\n     * IMPORTANT: because control is transferred to `recipient`, care must be\n     * taken to not create reentrancy vulnerabilities. Consider using\n     * {ReentrancyGuard} or the\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n     */\n    function sendValue(address payable recipient, uint256 amount) internal {\n        require(address(this).balance \u003e= amount, \"Address: insufficient balance\");\n\n        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value\n        (bool success, ) = recipient.call{ value: amount }(\"\");\n        require(success, \"Address: unable to send value, recipient may have reverted\");\n    }\n\n    /**\n     * @dev Performs a Solidity function call using a low level `call`. A\n     * plain`call` is an unsafe replacement for a function call: use this\n     * function instead.\n     *\n     * If `target` reverts with a revert reason, it is bubbled up by this\n     * function (like regular Solidity function calls).\n     *\n     * Returns the raw returned data. To convert to the expected return value,\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n     *\n     * Requirements:\n     *\n     * - `target` must be a contract.\n     * - calling `target` with `data` must not revert.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n      return functionCall(target, data, \"Address: low-level call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n     * `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, 0, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but also transferring `value` wei to `target`.\n     *\n     * Requirements:\n     *\n     * - the calling contract must have an ETH balance of at least `value`.\n     * - the called Solidity function must be `payable`.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {\n        require(address(this).balance \u003e= value, \"Address: insufficient balance for call\");\n        require(isContract(target), \"Address: call to non-contract\");\n\n        // solhint-disable-next-line avoid-low-level-calls\n        (bool success, bytes memory returndata) = target.call{ value: value }(data);\n        return _verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {\n        return functionStaticCall(target, data, \"Address: low-level static call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {\n        require(isContract(target), \"Address: static call to non-contract\");\n\n        // solhint-disable-next-line avoid-low-level-calls\n        (bool success, bytes memory returndata) = target.staticcall(data);\n        return _verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {\n        return functionDelegateCall(target, data, \"Address: low-level delegate call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\n        require(isContract(target), \"Address: delegate call to non-contract\");\n\n        // solhint-disable-next-line avoid-low-level-calls\n        (bool success, bytes memory returndata) = target.delegatecall(data);\n        return _verifyCallResult(success, returndata, errorMessage);\n    }\n\n    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {\n        if (success) {\n            return returndata;\n        } else {\n            // Look for revert reason and bubble it up if present\n            if (returndata.length \u003e 0) {\n                // The easiest way to bubble the revert reason is using memory via assembly\n\n                // solhint-disable-next-line no-inline-assembly\n                assembly {\n                    let returndata_size := mload(returndata)\n                    revert(add(32, returndata), returndata_size)\n                }\n            } else {\n                revert(errorMessage);\n            }\n        }\n    }\n}\n"},"Buffer.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\n// https://github.com/ensdomains/buffer\n\npragma solidity ^0.7.0;\n\n/**\n * @dev A library for working with mutable byte buffers in Solidity.\n *\n * Byte buffers are mutable and expandable, and provide a variety of primitives\n * for writing to them. At any time you can fetch a bytes object containing the\n * current contents of the buffer. The bytes object should not be stored between\n * operations, as it may change due to resizing of the buffer.\n */\nlibrary Buffer {\n    /**\n     * @dev Represents a mutable buffer. Buffers have a current value (buf) and\n     *      a capacity. The capacity may be longer than the current value, in\n     *      which case it can be extended without the need to allocate more memory.\n     */\n    struct buffer {\n        bytes buf;\n        uint capacity;\n    }\n\n    /**\n     * @dev Initializes a buffer with an initial capacity.a co\n     * @param buf The buffer to initialize.\n     * @param capacity The number of bytes of space to allocate the buffer.\n     * @return The buffer, for chaining.\n     */\n    function init(buffer memory buf, uint capacity) internal pure returns (buffer memory) {\n        if (capacity % 32 != 0) {\n            capacity += 32 - (capacity % 32);\n        }\n        // Allocate space for the buffer data\n        buf.capacity = capacity;\n        assembly {\n            let ptr := mload(0x40)\n            mstore(buf, ptr)\n            mstore(ptr, 0)\n            mstore(0x40, add(32, add(ptr, capacity)))\n        }\n        return buf;\n    }\n\n\n    /**\n     * @dev Writes a byte string to a buffer. Resizes if doing so would exceed\n     *      the capacity of the buffer.\n     * @param buf The buffer to append to.\n     * @param off The start offset to write to.\n     * @param rawData The data to append.\n     * @param len The number of bytes to copy.\n     * @return The original buffer, for chaining.\n     */\n    function writeRawBytes(\n        buffer memory buf,\n        uint off,\n        bytes memory rawData,\n        uint offData,\n        uint len\n    ) internal pure returns (buffer memory) {\n        if (off + len \u003e buf.capacity) {\n            resize(buf, max(buf.capacity, len + off) * 2);\n        }\n\n        uint dest;\n        uint src;\n        assembly {\n            // Memory address of the buffer data\n            let bufptr := mload(buf)\n            // Length of existing buffer data\n            let buflen := mload(bufptr)\n            // Start address = buffer address + offset + sizeof(buffer length)\n            dest := add(add(bufptr, 32), off)\n            // Update buffer length if we\u0027re extending it\n            if gt(add(len, off), buflen) {\n                mstore(bufptr, add(len, off))\n            }\n            src := add(rawData, offData)\n        }\n\n        // Copy word-length chunks while possible\n        for (; len \u003e= 32; len -= 32) {\n            assembly {\n                mstore(dest, mload(src))\n            }\n            dest += 32;\n            src += 32;\n        }\n\n        // Copy remaining bytes\n        uint mask = 256**(32 - len) - 1;\n        assembly {\n            let srcpart := and(mload(src), not(mask))\n            let destpart := and(mload(dest), mask)\n            mstore(dest, or(destpart, srcpart))\n        }\n\n        return buf;\n    }\n\n    /**\n     * @dev Writes a byte string to a buffer. Resizes if doing so would exceed\n     *      the capacity of the buffer.\n     * @param buf The buffer to append to.\n     * @param off The start offset to write to.\n     * @param data The data to append.\n     * @param len The number of bytes to copy.\n     * @return The original buffer, for chaining.\n     */\n    function write(buffer memory buf, uint off, bytes memory data, uint len) internal pure returns (buffer memory) {\n        require(len \u003c= data.length);\n\n        if (off + len \u003e buf.capacity) {\n            resize(buf, max(buf.capacity, len + off) * 2);\n        }\n\n        uint dest;\n        uint src;\n        assembly {\n        // Memory address of the buffer data\n            let bufptr := mload(buf)\n        // Length of existing buffer data\n            let buflen := mload(bufptr)\n        // Start address = buffer address + offset + sizeof(buffer length)\n            dest := add(add(bufptr, 32), off)\n        // Update buffer length if we\u0027re extending it\n            if gt(add(len, off), buflen) {\n                mstore(bufptr, add(len, off))\n            }\n            src := add(data, 32)\n        }\n\n        // Copy word-length chunks while possible\n        for (; len \u003e= 32; len -= 32) {\n            assembly {\n                mstore(dest, mload(src))\n            }\n            dest += 32;\n            src += 32;\n        }\n\n        // Copy remaining bytes\n        uint mask = 256**(32 - len) - 1;\n        assembly {\n            let srcpart := and(mload(src), not(mask))\n            let destpart := and(mload(dest), mask)\n            mstore(dest, or(destpart, srcpart))\n        }\n\n        return buf;\n    }\n\n    function append(buffer memory buf, bytes memory data) internal pure returns (buffer memory) {\n        return write(buf, buf.buf.length, data, data.length);\n    }\n\n    function resize(buffer memory buf, uint capacity) private pure {\n        bytes memory oldbuf = buf.buf;\n        init(buf, capacity);\n        append(buf, oldbuf);\n    }\n\n    function max(uint a, uint b) private pure returns (uint) {\n        if (a \u003e b) {\n            return a;\n        }\n        return b;\n    }\n}\n"},"Context.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity \u003e=0.6.0 \u003c0.8.0;\n\n/*\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with GSN meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n    function _msgSender() internal view virtual returns (address payable) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes memory) {\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\n        return msg.data;\n    }\n}\n"},"IERC20.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n    /**\n     * @dev Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @dev Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @dev Moves `amount` tokens from the caller\u0027s account to `recipient`.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transfer(address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Returns the remaining number of tokens that `spender` will be\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\n     * zero by default.\n     *\n     * This value changes when {approve} or {transferFrom} are called.\n     */\n    function allowance(address owner, address spender) external view returns (uint256);\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the caller\u0027s tokens.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\n     * that someone may use both the old and the new allowance by unfortunate\n     * transaction ordering. One possible solution to mitigate this race\n     * condition is to first reduce the spender\u0027s allowance to 0 and set the\n     * desired value afterwards:\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address spender, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Moves `amount` tokens from `sender` to `recipient` using the\n     * allowance mechanism. `amount` is then deducted from the caller\u0027s\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\n     * another (`to`).\n     *\n     * Note that `value` may be zero.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 value);\n\n    /**\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n     * a call to {approve}. `value` is the new allowance.\n     */\n    event Approval(address indexed owner, address indexed spender, uint256 value);\n}\n"},"ILayerZeroEndpoint.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.5.0;\n\nimport \"./ILayerZeroUserApplicationConfig.sol\";\n\ninterface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {\n    // @notice send a LayerZero message to the specified address at a LayerZero endpoint.\n    // @param _dstChainId - the destination chain identifier\n    // @param _destination - the address on destination chain (in bytes). address length/format may vary by chains\n    // @param _payload - a custom bytes payload to send to the destination contract\n    // @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address\n    // @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction\n    // @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination\n    function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;\n\n    // @notice used by the messaging library to publish verified payload\n    // @param _srcChainId - the source chain identifier\n    // @param _srcAddress - the source contract (as bytes) at the source chain\n    // @param _dstAddress - the address on destination chain\n    // @param _nonce - the unbound message ordering nonce\n    // @param _gasLimit - the gas limit for external contract execution\n    // @param _payload - verified payload to send to the destination contract\n    function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _payload) external;\n\n    // @notice get the inboundNonce of a receiver from a source chain which could be EVM or non-EVM chain\n    // @param _srcChainId - the source chain identifier\n    // @param _srcAddress - the source chain contract address\n    function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (uint64);\n\n    // @notice get the outboundNonce from this source chain which, consequently, is always an EVM\n    // @param _srcAddress - the source chain contract address\n    function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view returns (uint64);\n\n    // @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery\n    // @param _dstChainId - the destination chain identifier\n    // @param _userApplication - the user app address on this EVM chain\n    // @param _payload - the custom message to send over LayerZero\n    // @param _payInZRO - if false, user app pays the protocol fee in native token\n    // @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain\n    function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);\n\n    // @notice get this Endpoint\u0027s immutable source identifier\n    function getChainId() external view returns (uint16);\n\n    // @notice the interface to retry failed message on this Endpoint destination\n    // @param _srcChainId - the source chain identifier\n    // @param _srcAddress - the source chain contract address\n    // @param _payload - the payload to be retried\n    function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _payload) external;\n\n    // @notice query if any STORED payload (message blocking) at the endpoint.\n    // @param _srcChainId - the source chain identifier\n    // @param _srcAddress - the source chain contract address\n    function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool);\n\n    // @notice query if the _libraryAddress is valid for sending msgs.\n    // @param _userApplication - the user app address on this EVM chain\n    function getSendLibraryAddress(address _userApplication) external view returns (address);\n\n    // @notice query if the _libraryAddress is valid for receiving msgs.\n    // @param _userApplication - the user app address on this EVM chain\n    function getReceiveLibraryAddress(address _userApplication) external view returns (address);\n\n    // @notice query if the non-reentrancy guard for send() is on\n    // @return true if the guard is on. false otherwise\n    function isSendingPayload() external view returns (bool);\n\n    // @notice query if the non-reentrancy guard for receive() is on\n    // @return true if the guard is on. false otherwise\n    function isReceivingPayload() external view returns (bool);\n\n    // @notice get the configuration of the LayerZero messaging library of the specified version\n    // @param _version - messaging library version\n    // @param _chainId - the chainId for the pending config change\n    // @param _userApplication - the contract address of the user application\n    // @param _configType - type of configuration. every messaging library has its own convention.\n    function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);\n\n    // @notice get the send() LayerZero messaging library version\n    // @param _userApplication - the contract address of the user application\n    function getSendVersion(address _userApplication) external view returns (uint16);\n\n    // @notice get the lzReceive() LayerZero messaging library version\n    // @param _userApplication - the contract address of the user application\n    function getReceiveVersion(address _userApplication) external view returns (uint16);\n}\n"},"ILayerZeroMessagingLibrary.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.7.0;\n\nimport \"./ILayerZeroUserApplicationConfig.sol\";\n\ninterface ILayerZeroMessagingLibrary {\n    // send(), messages will be inflight.\n    function send(address _userApplication, uint64 _lastNonce, uint16 _chainId, bytes calldata _destination, bytes calldata _payload, address payable refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;\n\n    // estimate native fee at the send side\n    function estimateFees(uint16 _chainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);\n\n    //---------------------------------------------------------------------------\n    // setConfig / getConfig are User Application (UA) functions to specify Oracle, Relayer, blockConfirmations, libraryVersion\n    function setConfig(uint16 _chainId, address _userApplication, uint _configType, bytes calldata _config) external;\n\n    function getConfig(uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);\n}\n"},"ILayerZeroMessagingLibraryV2.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.7.0;\n\nimport \"./ILayerZeroUserApplicationConfig.sol\";\nimport \"./ILayerZeroMessagingLibrary.sol\";\n\ninterface ILayerZeroMessagingLibraryV2 is ILayerZeroMessagingLibrary {\n    function getOutboundNonce(uint16 _chainId, bytes calldata _path) external view returns (uint64);\n}\n"},"ILayerZeroOracleV2.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.7.0;\n\ninterface ILayerZeroOracleV2 {\n    // @notice query price and assign jobs at the same time\n    // @param _dstChainId - the destination endpoint identifier\n    // @param _outboundProofType - the proof type identifier to specify proof to be relayed\n    // @param _outboundBlockConfirmation - block confirmation delay before relaying blocks\n    // @param _userApplication - the source sending contract address\n    function assignJob(uint16 _dstChainId, uint16 _outboundProofType, uint64 _outboundBlockConfirmation, address _userApplication) external returns (uint price);\n\n    // @notice query the oracle price for relaying block information to the destination chain\n    // @param _dstChainId the destination endpoint identifier\n    // @param _outboundProofType the proof type identifier to specify the data to be relayed\n    // @param _outboundBlockConfirmation - block confirmation delay before relaying blocks\n    // @param _userApplication - the source sending contract address\n    function getFee(uint16 _dstChainId, uint16 _outboundProofType, uint64 _outboundBlockConfirmation, address _userApplication) external view returns (uint price);\n\n    // @notice withdraw the accrued fee in ultra light node\n    // @param _to - the fee receiver\n    // @param _amount - the withdrawal amount\n    function withdrawFee(address payable _to, uint _amount) external;\n}\n"},"ILayerZeroReceiver.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.5.0;\n\ninterface ILayerZeroReceiver {\n    // @notice LayerZero endpoint will invoke this function to deliver the message on the destination\n    // @param _srcChainId - the source endpoint identifier\n    // @param _srcAddress - the source sending contract address from the source chain\n    // @param _nonce - the ordered message nonce\n    // @param _payload - the signed payload is the UA bytes has encoded to be sent\n    function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) external;\n}\n"},"ILayerZeroRelayerV2.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.7.0;\n\ninterface ILayerZeroRelayerV2 {\n    // @notice query price and assign jobs at the same time\n    // @param _dstChainId - the destination endpoint identifier\n    // @param _outboundProofType - the proof type identifier to specify proof to be relayed\n    // @param _userApplication - the source sending contract address. relayers may apply price discrimination to user apps\n    // @param _payloadSize - the length of the payload. it is an indicator of gas usage for relaying cross-chain messages\n    // @param _adapterParams - optional parameters for extra service plugins, e.g. sending dust tokens at the destination chain\n    function assignJob(uint16 _dstChainId, uint16 _outboundProofType, address _userApplication, uint _payloadSize, bytes calldata _adapterParams) external returns (uint price);\n\n    // @notice query the relayer price for relaying the payload and its proof to the destination chain\n    // @param _dstChainId - the destination endpoint identifier\n    // @param _outboundProofType - the proof type identifier to specify proof to be relayed\n    // @param _userApplication - the source sending contract address. relayers may apply price discrimination to user apps\n    // @param _payloadSize - the length of the payload. it is an indicator of gas usage for relaying cross-chain messages\n    // @param _adapterParams - optional parameters for extra service plugins, e.g. sending dust tokens at the destination chain\n    function getFee(uint16 _dstChainId, uint16 _outboundProofType, address _userApplication, uint _payloadSize, bytes calldata _adapterParams) external view returns (uint price);\n\n    // @notice withdraw the accrued fee in ultra light node\n    // @param _to - the fee receiver\n    // @param _amount - the withdrawal amount\n    function withdrawFee(address payable _to, uint _amount) external;\n}\n"},"ILayerZeroTreasury.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.5.0;\n\ninterface ILayerZeroTreasury {\n    function getFees(bool payInZro, uint relayerFee, uint oracleFee) external view returns (uint);\n}\n"},"ILayerZeroUltraLightNodeV2.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.7.0;\npragma abicoder v2;\n\ninterface ILayerZeroUltraLightNodeV2 {\n    // Relayer functions\n    function validateTransactionProof(uint16 _srcChainId, address _dstAddress, uint _gasLimit, bytes32 _lookupHash, bytes32 _blockData, bytes calldata _transactionProof) external;\n\n    // an Oracle delivers the block data using updateHash()\n    function updateHash(uint16 _srcChainId, bytes32 _lookupHash, uint _confirmations, bytes32 _blockData) external;\n\n    // can only withdraw the receivable of the msg.sender\n    function withdrawNative(address payable _to, uint _amount) external;\n\n    function withdrawZRO(address _to, uint _amount) external;\n\n    // view functions\n    function getAppConfig(uint16 _remoteChainId, address _userApplicationAddress) external view returns (ApplicationConfiguration memory);\n\n    function accruedNativeFee(address _address) external view returns (uint);\n\n    struct ApplicationConfiguration {\n        uint16 inboundProofLibraryVersion;\n        uint64 inboundBlockConfirmations;\n        address relayer;\n        uint16 outboundProofType;\n        uint64 outboundBlockConfirmations;\n        address oracle;\n    }\n\n    event HashReceived(uint16 indexed srcChainId, address indexed oracle, bytes32 lookupHash, bytes32 blockData, uint confirmations);\n    event RelayerParams(bytes adapterParams, uint16 outboundProofType);\n    event Packet(bytes payload);\n    event InvalidDst(uint16 indexed srcChainId, bytes srcAddress, address indexed dstAddress, uint64 nonce, bytes32 payloadHash);\n    event PacketReceived(uint16 indexed srcChainId, bytes srcAddress, address indexed dstAddress, uint64 nonce, bytes32 payloadHash);\n    event AppConfigUpdated(address indexed userApplication, uint indexed configType, bytes newConfig);\n    event AddInboundProofLibraryForChain(uint16 indexed chainId, address lib);\n    event EnableSupportedOutboundProof(uint16 indexed chainId, uint16 proofType);\n    event SetChainAddressSize(uint16 indexed chainId, uint size);\n    event SetDefaultConfigForChainId(uint16 indexed chainId, uint16 inboundProofLib, uint64 inboundBlockConfirm, address relayer, uint16 outboundProofType, uint64 outboundBlockConfirm, address oracle);\n    event SetDefaultAdapterParamsForChainId(uint16 indexed chainId, uint16 indexed proofType, bytes adapterParams);\n    event SetLayerZeroToken(address indexed tokenAddress);\n    event SetRemoteUln(uint16 indexed chainId, bytes32 uln);\n    event SetTreasury(address indexed treasuryAddress);\n    event WithdrawZRO(address indexed msgSender, address indexed to, uint amount);\n    event WithdrawNative(address indexed msgSender, address indexed to, uint amount);\n}\n"},"ILayerZeroUserApplicationConfig.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.5.0;\n\ninterface ILayerZeroUserApplicationConfig {\n    // @notice set the configuration of the LayerZero messaging library of the specified version\n    // @param _version - messaging library version\n    // @param _chainId - the chainId for the pending config change\n    // @param _configType - type of configuration. every messaging library has its own convention.\n    // @param _config - configuration in the bytes. can encode arbitrary content.\n    function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external;\n\n    // @notice set the send() LayerZero messaging library version to _version\n    // @param _version - new messaging library version\n    function setSendVersion(uint16 _version) external;\n\n    // @notice set the lzReceive() LayerZero messaging library version to _version\n    // @param _version - new messaging library version\n    function setReceiveVersion(uint16 _version) external;\n\n    // @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload\n    // @param _srcChainId - the chainId of the source chain\n    // @param _srcAddress - the contract address of the source contract at the source chain\n    function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external;\n}\n"},"ILayerZeroValidationLibrary.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity \u003e=0.7.0;\npragma abicoder v2;\n\nimport \"./LayerZeroPacket.sol\";\n\ninterface ILayerZeroValidationLibrary {\n    function validateProof(bytes32 blockData, bytes calldata _data, uint _remoteAddressSize) external returns (LayerZeroPacket.Packet memory packet);\n}\n"},"LayerZeroPacket.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity 0.7.6;\n\nimport \"./Buffer.sol\";\nimport \"./SafeMath.sol\";\n\nlibrary LayerZeroPacket {\n    using Buffer for Buffer.buffer;\n    using SafeMath for uint;\n\n    struct Packet {\n        uint16 srcChainId;\n        uint16 dstChainId;\n        uint64 nonce;\n        address dstAddress;\n        bytes srcAddress;\n        bytes32 ulnAddress;\n        bytes payload;\n    }\n\n    function getPacket(\n        bytes memory data,\n        uint16 srcChain,\n        uint sizeOfSrcAddress,\n        bytes32 ulnAddress\n    ) internal pure returns (LayerZeroPacket.Packet memory) {\n        uint16 dstChainId;\n        address dstAddress;\n        uint size;\n        uint64 nonce;\n\n        // The log consists of the destination chain id and then a bytes payload\n        //      0--------------------------------------------31\n        // 0   |  total bytes size\n        // 32  |  destination chain id\n        // 64  |  bytes offset\n        // 96  |  bytes array size\n        // 128 |  payload\n        assembly {\n            dstChainId := mload(add(data, 32))\n            size := mload(add(data, 96)) /// size of the byte array\n            nonce := mload(add(data, 104)) // offset to convert to uint64  128  is index -24\n            dstAddress := mload(add(data, sub(add(128, sizeOfSrcAddress), 4))) // offset to convert to address 12 -8\n        }\n\n        Buffer.buffer memory srcAddressBuffer;\n        srcAddressBuffer.init(sizeOfSrcAddress);\n        srcAddressBuffer.writeRawBytes(0, data, 136, sizeOfSrcAddress); // 128 + 8\n\n        uint payloadSize = size.sub(28).sub(sizeOfSrcAddress);\n        Buffer.buffer memory payloadBuffer;\n        payloadBuffer.init(payloadSize);\n        payloadBuffer.writeRawBytes(0, data, sizeOfSrcAddress.add(156), payloadSize); // 148 + 8\n        return LayerZeroPacket.Packet(srcChain, dstChainId, nonce, dstAddress, srcAddressBuffer.buf, ulnAddress, payloadBuffer.buf);\n    }\n\n    function getPacketV2(\n        bytes memory data,\n        uint sizeOfSrcAddress,\n        bytes32 ulnAddress\n    ) internal pure returns (LayerZeroPacket.Packet memory) {\n        // packet def: abi.encodePacked(nonce, srcChain, srcAddress, dstChain, dstAddress, payload);\n        // data def: abi.encode(packet) = offset(32) + length(32) + packet\n        //              if from EVM\n        // 0 - 31       0 - 31          |  total bytes size\n        // 32 - 63      32 - 63         |  location\n        // 64 - 95      64 - 95         |  size of the packet\n        // 96 - 103     96 - 103        |  nonce\n        // 104 - 105    104 - 105       |  srcChainId\n        // 106 - P      106 - 125       |  srcAddress, where P = 106 + sizeOfSrcAddress - 1,\n        // P+1 - P+2    126 - 127       |  dstChainId\n        // P+3 - P+22   128 - 147       |  dstAddress\n        // P+23 - END   148 - END       |  payload\n\n        // decode the packet\n        uint256 realSize;\n        uint64 nonce;\n        uint16 srcChain;\n        uint16 dstChain;\n        address dstAddress;\n        assembly {\n            realSize := mload(add(data, 64))\n            nonce := mload(add(data, 72)) // 104 - 32\n            srcChain := mload(add(data, 74)) // 106 - 32\n            dstChain := mload(add(data, add(76, sizeOfSrcAddress))) // P + 3 - 32 = 105 + size + 3 - 32 = 76 + size\n            dstAddress := mload(add(data, add(96, sizeOfSrcAddress))) // P + 23 - 32 = 105 + size + 23 - 32 = 96 + size\n        }\n\n        require(srcChain != 0, \"LayerZeroPacket: invalid packet\");\n\n        Buffer.buffer memory srcAddressBuffer;\n        srcAddressBuffer.init(sizeOfSrcAddress);\n        srcAddressBuffer.writeRawBytes(0, data, 106, sizeOfSrcAddress);\n\n        uint nonPayloadSize = sizeOfSrcAddress.add(32);// 2 + 2 + 8 + 20, 32 + 20 = 52 if sizeOfSrcAddress == 20\n        uint payloadSize = realSize.sub(nonPayloadSize);\n        Buffer.buffer memory payloadBuffer;\n        payloadBuffer.init(payloadSize);\n        payloadBuffer.writeRawBytes(0, data, nonPayloadSize.add(96), payloadSize);\n\n        return LayerZeroPacket.Packet(srcChain, dstChain, nonce, dstAddress, srcAddressBuffer.buf, ulnAddress, payloadBuffer.buf);\n    }\n\n    function getPacketV3(\n        bytes memory data,\n        uint sizeOfSrcAddress,\n        bytes32 ulnAddress\n    ) internal pure returns (LayerZeroPacket.Packet memory) {\n        // data def: abi.encodePacked(nonce, srcChain, srcAddress, dstChain, dstAddress, payload);\n        //              if from EVM\n        // 0 - 31       0 - 31          |  total bytes size\n        // 32 - 39      32 - 39         |  nonce\n        // 40 - 41      40 - 41         |  srcChainId\n        // 42 - P       42 - 61         |  srcAddress, where P = 41 + sizeOfSrcAddress,\n        // P+1 - P+2    62 - 63         |  dstChainId\n        // P+3 - P+22   64 - 83         |  dstAddress\n        // P+23 - END   84 - END        |  payload\n\n        // decode the packet\n        uint256 realSize = data.length;\n        uint nonPayloadSize = sizeOfSrcAddress.add(32);// 2 + 2 + 8 + 20, 32 + 20 = 52 if sizeOfSrcAddress == 20\n        require(realSize \u003e= nonPayloadSize, \"LayerZeroPacket: invalid packet\");\n        uint payloadSize = realSize - nonPayloadSize;\n\n        uint64 nonce;\n        uint16 srcChain;\n        uint16 dstChain;\n        address dstAddress;\n        assembly {\n            nonce := mload(add(data, 8)) // 40 - 32\n            srcChain := mload(add(data, 10)) // 42 - 32\n            dstChain := mload(add(data, add(12, sizeOfSrcAddress))) // P + 3 - 32 = 41 + size + 3 - 32 = 12 + size\n            dstAddress := mload(add(data, add(32, sizeOfSrcAddress))) // P + 23 - 32 = 41 + size + 23 - 32 = 32 + size\n        }\n\n        require(srcChain != 0, \"LayerZeroPacket: invalid packet\");\n\n        Buffer.buffer memory srcAddressBuffer;\n        srcAddressBuffer.init(sizeOfSrcAddress);\n        srcAddressBuffer.writeRawBytes(0, data, 42, sizeOfSrcAddress);\n\n        Buffer.buffer memory payloadBuffer;\n        if (payloadSize \u003e 0) {\n            payloadBuffer.init(payloadSize);\n            payloadBuffer.writeRawBytes(0, data, nonPayloadSize.add(32), payloadSize);\n        }\n\n        return LayerZeroPacket.Packet(srcChain, dstChain, nonce, dstAddress, srcAddressBuffer.buf, ulnAddress, payloadBuffer.buf);\n    }\n}\n"},"NonceContract.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity 0.7.6;\n\nimport \"./ILayerZeroEndpoint.sol\";\n\ncontract NonceContract {\n    ILayerZeroEndpoint public immutable endpoint;\n    // outboundNonce = [dstChainId][remoteAddress + localAddress]\n    mapping(uint16 =\u003e mapping(bytes =\u003e uint64)) public outboundNonce;\n\n    constructor(address _endpoint) {\n        endpoint = ILayerZeroEndpoint(_endpoint);\n    }\n\n    function increment(uint16 _chainId, address _ua, bytes calldata _path) external returns (uint64) {\n        require(endpoint.getSendLibraryAddress(_ua) == msg.sender, \"NonceContract: msg.sender is not valid sendlibrary\");\n        return ++outboundNonce[_chainId][_path];\n    }\n}\n"},"Ownable.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\nimport \"./Context.sol\";\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract Ownable is Context {\n    address private _owner;\n\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n    constructor () {\n        address msgSender = _msgSender();\n        _owner = msgSender;\n        emit OwnershipTransferred(address(0), msgSender);\n    }\n\n    /**\n     * @dev Returns the address of the current owner.\n     */\n    function owner() public view virtual returns (address) {\n        return _owner;\n    }\n\n    /**\n     * @dev Throws if called by any account other than the owner.\n     */\n    modifier onlyOwner() {\n        require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n        _;\n    }\n\n    /**\n     * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby removing any functionality that is only available to the owner.\n     */\n    function renounceOwnership() public virtual onlyOwner {\n        emit OwnershipTransferred(_owner, address(0));\n        _owner = address(0);\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual onlyOwner {\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n        emit OwnershipTransferred(_owner, newOwner);\n        _owner = newOwner;\n    }\n}\n"},"ReentrancyGuard.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\n/**\n * @dev Contract module that helps prevent reentrant calls to a function.\n *\n * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier\n * available, which can be applied to functions to make sure there are no nested\n * (reentrant) calls to them.\n *\n * Note that because there is a single `nonReentrant` guard, functions marked as\n * `nonReentrant` may not call one another. This can be worked around by making\n * those functions `private`, and then adding `external` `nonReentrant` entry\n * points to them.\n *\n * TIP: If you would like to learn more about reentrancy and alternative ways\n * to protect against it, check out our blog post\n * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].\n */\nabstract contract ReentrancyGuard {\n    // Booleans are more expensive than uint256 or any type that takes up a full\n    // word because each write operation emits an extra SLOAD to first read the\n    // slot\u0027s contents, replace the bits taken up by the boolean, and then write\n    // back. This is the compiler\u0027s defense against contract upgrades and\n    // pointer aliasing, and it cannot be disabled.\n\n    // The values being non-zero value makes deployment a bit more expensive,\n    // but in exchange the refund on every call to nonReentrant will be lower in\n    // amount. Since refunds are capped to a percentage of the total\n    // transaction\u0027s gas, it is best to keep them low in cases like this one, to\n    // increase the likelihood of the full refund coming into effect.\n    uint256 private constant _NOT_ENTERED = 1;\n    uint256 private constant _ENTERED = 2;\n\n    uint256 private _status;\n\n    constructor () {\n        _status = _NOT_ENTERED;\n    }\n\n    /**\n     * @dev Prevents a contract from calling itself, directly or indirectly.\n     * Calling a `nonReentrant` function from another `nonReentrant`\n     * function is not supported. It is possible to prevent this from happening\n     * by making the `nonReentrant` function external, and make it call a\n     * `private` function that does the actual work.\n     */\n    modifier nonReentrant() {\n        // On the first call to nonReentrant, _notEntered will be true\n        require(_status != _ENTERED, \"ReentrancyGuard: reentrant call\");\n\n        // Any calls to nonReentrant after this point will fail\n        _status = _ENTERED;\n\n        _;\n\n        // By storing the original value once again, a refund is triggered (see\n        // https://eips.ethereum.org/EIPS/eip-2200)\n        _status = _NOT_ENTERED;\n    }\n}\n"},"SafeERC20.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\nimport \"./IERC20.sol\";\nimport \"./SafeMath.sol\";\nimport \"./Address.sol\";\n\n/**\n * @title SafeERC20\n * @dev Wrappers around ERC20 operations that throw on failure (when the token\n * contract returns false). Tokens that return no value (and instead revert or\n * throw on failure) are also supported, non-reverting calls are assumed to be\n * successful.\n * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,\n * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.\n */\nlibrary SafeERC20 {\n    using SafeMath for uint256;\n    using Address for address;\n\n    function safeTransfer(IERC20 token, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));\n    }\n\n    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));\n    }\n\n    /**\n     * @dev Deprecated. This function has issues similar to the ones found in\n     * {IERC20-approve}, and its usage is discouraged.\n     *\n     * Whenever possible, use {safeIncreaseAllowance} and\n     * {safeDecreaseAllowance} instead.\n     */\n    function safeApprove(IERC20 token, address spender, uint256 value) internal {\n        // safeApprove should only be called when setting an initial allowance,\n        // or when resetting it to zero. To increase and decrease it, use\n        // \u0027safeIncreaseAllowance\u0027 and \u0027safeDecreaseAllowance\u0027\n        // solhint-disable-next-line max-line-length\n        require((value == 0) || (token.allowance(address(this), spender) == 0),\n            \"SafeERC20: approve from non-zero to non-zero allowance\"\n        );\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));\n    }\n\n    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).add(value);\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 newAllowance = token.allowance(address(this), spender).sub(value, \"SafeERC20: decreased allowance below zero\");\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    /**\n     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement\n     * on the return value: the return value is optional (but if data is returned, it must not be false).\n     * @param token The token targeted by the call.\n     * @param data The call data (encoded using abi.encode or one of its variants).\n     */\n    function _callOptionalReturn(IERC20 token, bytes memory data) private {\n        // We need to perform a low level call here, to bypass Solidity\u0027s return data size checking mechanism, since\n        // we\u0027re implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that\n        // the target address contains contract code and also asserts for success in the low-level call.\n\n        bytes memory returndata = address(token).functionCall(data, \"SafeERC20: low-level call failed\");\n        if (returndata.length \u003e 0) { // Return data is optional\n            // solhint-disable-next-line max-line-length\n            require(abi.decode(returndata, (bool)), \"SafeERC20: ERC20 operation did not succeed\");\n        }\n    }\n}\n"},"SafeMath.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\n/**\n * @dev Wrappers over Solidity\u0027s arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it\u0027s recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        uint256 c = a + b;\n        if (c \u003c a) return (false, 0);\n        return (true, c);\n    }\n\n    /**\n     * @dev Returns the substraction of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        if (b \u003e a) return (false, 0);\n        return (true, a - b);\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        // Gas optimization: this is cheaper than requiring \u0027a\u0027 not being zero, but the\n        // benefit is lost if \u0027b\u0027 is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) return (true, 0);\n        uint256 c = a * b;\n        if (c / a != b) return (false, 0);\n        return (true, c);\n    }\n\n    /**\n     * @dev Returns the division of two unsigned integers, with a division by zero flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        if (b == 0) return (false, 0);\n        return (true, a / b);\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        if (b == 0) return (false, 0);\n        return (true, a % b);\n    }\n\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `+` operator.\n     *\n     * Requirements:\n     *\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c \u003e= a, \"SafeMath: addition overflow\");\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b \u003c= a, \"SafeMath: subtraction overflow\");\n        return a - b;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `*` operator.\n     *\n     * Requirements:\n     *\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        if (a == 0) return 0;\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers, reverting on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b \u003e 0, \"SafeMath: division by zero\");\n        return a / b;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * reverting when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        require(b \u003e 0, \"SafeMath: modulo by zero\");\n        return a % b;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n     * overflow (when the result is negative).\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {trySub}.\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003c= a, errorMessage);\n        return a - b;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers, reverting with custom message on\n     * division by zero. The result is rounded towards zero.\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {tryDiv}.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003e 0, errorMessage);\n        return a / b;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * reverting with custom message when dividing by zero.\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {tryMod}.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003e 0, errorMessage);\n        return a % b;\n    }\n}\n"},"UltraLightNodeV2.sol":{"content":"// SPDX-License-Identifier: BUSL-1.1\n\npragma solidity 0.7.6;\npragma abicoder v2;\n\nimport \"./Ownable.sol\";\nimport \"./SafeMath.sol\";\nimport \"./ReentrancyGuard.sol\";\nimport \"./IERC20.sol\";\nimport \"./SafeERC20.sol\";\n\nimport \"./ILayerZeroValidationLibrary.sol\";\nimport \"./ILayerZeroReceiver.sol\";\nimport \"./ILayerZeroTreasury.sol\";\nimport \"./ILayerZeroEndpoint.sol\";\n// v2\nimport \"./ILayerZeroMessagingLibraryV2.sol\";\nimport \"./ILayerZeroOracleV2.sol\";\nimport \"./ILayerZeroUltraLightNodeV2.sol\";\nimport \"./ILayerZeroRelayerV2.sol\";\nimport \"./NonceContract.sol\";\n\ncontract UltraLightNodeV2 is ILayerZeroMessagingLibraryV2, ILayerZeroUltraLightNodeV2, ReentrancyGuard, Ownable {\n    using SafeERC20 for IERC20;\n    using SafeMath for uint;\n\n    // Application config\n    uint public constant CONFIG_TYPE_INBOUND_PROOF_LIBRARY_VERSION = 1;\n    uint public constant CONFIG_TYPE_INBOUND_BLOCK_CONFIRMATIONS = 2;\n    uint public constant CONFIG_TYPE_RELAYER = 3;\n    uint public constant CONFIG_TYPE_OUTBOUND_PROOF_TYPE = 4;\n    uint public constant CONFIG_TYPE_OUTBOUND_BLOCK_CONFIRMATIONS = 5;\n    uint public constant CONFIG_TYPE_ORACLE = 6;\n\n    // Token and Contracts\n    IERC20 public layerZeroToken;\n    ILayerZeroTreasury public treasuryContract;\n\n    mapping(address =\u003e uint) public nativeFees;\n    uint public treasuryZROFees;\n\n    // User Application\n    mapping(address =\u003e mapping(uint16 =\u003e ApplicationConfiguration)) public appConfig; // app address =\u003e chainId =\u003e config\n    mapping(uint16 =\u003e ApplicationConfiguration) public defaultAppConfig; // default UA settings if no version specified\n    mapping(uint16 =\u003e mapping(uint16 =\u003e bytes)) public defaultAdapterParams;\n\n    // Validation\n    mapping(uint16 =\u003e mapping(uint16 =\u003e address)) public inboundProofLibrary; // chainId =\u003e library Id =\u003e inboundProofLibrary contract\n    mapping(uint16 =\u003e uint16) public maxInboundProofLibrary; // chainId =\u003e inboundProofLibrary\n    mapping(uint16 =\u003e mapping(uint16 =\u003e bool)) public supportedOutboundProof; // chainId =\u003e outboundProofType =\u003e enabled\n    mapping(uint16 =\u003e uint) public chainAddressSizeMap;\n    mapping(address =\u003e mapping(uint16 =\u003e mapping(bytes32 =\u003e mapping(bytes32 =\u003e uint)))) public hashLookup; //[oracle][srcChainId][blockhash][datahash] -\u003e confirmation\n    mapping(uint16 =\u003e bytes32) public ulnLookup; // remote ulns\n\n    ILayerZeroEndpoint public immutable endpoint;\n    uint16 public immutable localChainId;\n    NonceContract public immutable nonceContract;\n\n    constructor(address _endpoint, address _nonceContract, uint16 _localChainId) {\n        require(_endpoint != address(0x0), \"LayerZero: endpoint cannot be zero address\");\n        require(_nonceContract != address(0x0), \"LayerZero: nonceContract cannot be zero address\");\n        ILayerZeroEndpoint lzEndpoint = ILayerZeroEndpoint(_endpoint);\n        localChainId = _localChainId;\n        endpoint = lzEndpoint;\n        nonceContract = NonceContract(_nonceContract);\n    }\n\n    // only the endpoint can call SEND() and setConfig()\n    modifier onlyEndpoint() {\n        require(address(endpoint) == msg.sender, \"LayerZero: only endpoint\");\n        _;\n    }\n\n    //----------------------------------------------------------------------------------\n    // PROTOCOL\n    function validateTransactionProof(uint16 _srcChainId, address _dstAddress, uint _gasLimit, bytes32 _lookupHash, bytes32 _blockData, bytes calldata _transactionProof) external override {\n        // retrieve UA\u0027s configuration using the _dstAddress from arguments.\n        ApplicationConfiguration memory uaConfig = _getAppConfig(_srcChainId, _dstAddress);\n\n        // assert that the caller == UA\u0027s relayer\n        require(uaConfig.relayer == msg.sender, \"LayerZero: invalid relayer\");\n\n        LayerZeroPacket.Packet memory _packet;\n        uint remoteAddressSize = chainAddressSizeMap[_srcChainId];\n        require(remoteAddressSize != 0, \"LayerZero: incorrect remote address size\");\n        {\n            // assert that the data submitted by UA\u0027s oracle have no fewer confirmations than UA\u0027s configuration\n            uint storedConfirmations = hashLookup[uaConfig.oracle][_srcChainId][_lookupHash][_blockData];\n            require(storedConfirmations \u003e 0 \u0026\u0026 storedConfirmations \u003e= uaConfig.inboundBlockConfirmations, \"LayerZero: not enough block confirmations\");\n\n            // decode\n            address inboundProofLib = inboundProofLibrary[_srcChainId][uaConfig.inboundProofLibraryVersion];\n            _packet = ILayerZeroValidationLibrary(inboundProofLib).validateProof(_blockData, _transactionProof, remoteAddressSize);\n        }\n\n        // packet content assertion\n        require(ulnLookup[_srcChainId] == _packet.ulnAddress \u0026\u0026 _packet.ulnAddress != bytes32(0), \"LayerZero: invalid _packet.ulnAddress\");\n        require(_packet.srcChainId == _srcChainId, \"LayerZero: invalid srcChain Id\");\n        // failsafe because the remoteAddress size being passed into validateProof trims the address this should not hit\n        require(_packet.srcAddress.length == remoteAddressSize, \"LayerZero: invalid srcAddress size\");\n        require(_packet.dstChainId == localChainId, \"LayerZero: invalid dstChain Id\");\n        require(_packet.dstAddress == _dstAddress, \"LayerZero: invalid dstAddress\");\n\n        // if the dst is not a contract, then emit and return early. This will break inbound nonces, but this particular\n        // path is already broken and wont ever be able to deliver anyways\n        if (!_isContract(_dstAddress)) {\n            emit InvalidDst(_packet.srcChainId, _packet.srcAddress, _packet.dstAddress, _packet.nonce, keccak256(_packet.payload));\n            return;\n        }\n\n        bytes memory pathData = abi.encodePacked(_packet.srcAddress, _packet.dstAddress);\n        emit PacketReceived(_packet.srcChainId, _packet.srcAddress, _packet.dstAddress, _packet.nonce, keccak256(_packet.payload));\n        endpoint.receivePayload(_srcChainId, pathData, _dstAddress, _packet.nonce, _gasLimit, _packet.payload);\n    }\n\n    function send(address _ua, uint64, uint16 _dstChainId, bytes calldata _path, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable override onlyEndpoint {\n        address ua = _ua;\n        uint16 dstChainId = _dstChainId;\n        require(ulnLookup[dstChainId] != bytes32(0), \"LayerZero: dstChainId does not exist\");\n\n        bytes memory dstAddress;\n        uint64 nonce;\n        // code block for solving \u0027Stack Too Deep\u0027\n        {\n            uint chainAddressSize = chainAddressSizeMap[dstChainId];\n            // path = remoteAddress + localAddress\n            require(chainAddressSize != 0 \u0026\u0026 _path.length == 20 + chainAddressSize, \"LayerZero: incorrect remote address size\");\n            address srcInPath;\n            bytes memory path = _path; // copy to memory\n            assembly {\n                srcInPath := mload(add(add(path, 20), chainAddressSize)) // chainAddressSize + 20\n            }\n            require(ua == srcInPath, \"LayerZero: wrong path data\");\n            dstAddress = _path[0:chainAddressSize];\n            nonce = nonceContract.increment(dstChainId, ua, path);\n        }\n\n        bytes memory payload = _payload;\n        ApplicationConfiguration memory uaConfig = _getAppConfig(dstChainId, ua);\n\n        // compute all the fees\n        uint relayerFee = _handleRelayer(dstChainId, uaConfig, ua, payload.length, _adapterParams);\n        uint oracleFee = _handleOracle(dstChainId, uaConfig, ua);\n        uint nativeProtocolFee = _handleProtocolFee(relayerFee, oracleFee, ua, _zroPaymentAddress);\n\n        // total native fee, does not include ZRO protocol fee\n        uint totalNativeFee = relayerFee.add(oracleFee).add(nativeProtocolFee);\n\n        // assert the user has attached enough native token for this address\n        require(totalNativeFee \u003c= msg.value, \"LayerZero: not enough native for fees\");\n        // refund if they send too much\n        uint amount = msg.value.sub(totalNativeFee);\n        if (amount \u003e 0) {\n            (bool success, ) = _refundAddress.call{value: amount}(\"\");\n            require(success, \"LayerZero: failed to refund\");\n        }\n\n        // emit the data packet\n        bytes memory encodedPayload = abi.encodePacked(nonce, localChainId, ua, dstChainId, dstAddress, payload);\n        emit Packet(encodedPayload);\n    }\n\n    function _handleRelayer(uint16 _dstChainId, ApplicationConfiguration memory _uaConfig, address _ua, uint _payloadSize, bytes memory _adapterParams) internal returns (uint relayerFee) {\n        if (_adapterParams.length == 0) {\n            _adapterParams = defaultAdapterParams[_dstChainId][_uaConfig.outboundProofType];\n        }\n        address relayerAddress = _uaConfig.relayer;\n        ILayerZeroRelayerV2 relayer = ILayerZeroRelayerV2(relayerAddress);\n        relayerFee = relayer.assignJob(_dstChainId, _uaConfig.outboundProofType, _ua, _payloadSize, _adapterParams);\n\n        _creditNativeFee(relayerAddress, relayerFee);\n\n        // emit the param events\n        emit RelayerParams(_adapterParams, _uaConfig.outboundProofType);\n    }\n\n    function _handleOracle(uint16 _dstChainId, ApplicationConfiguration memory _uaConfig, address _ua) internal returns (uint oracleFee) {\n        address oracleAddress = _uaConfig.oracle;\n        oracleFee = ILayerZeroOracleV2(oracleAddress).assignJob(_dstChainId, _uaConfig.outboundProofType, _uaConfig.outboundBlockConfirmations, _ua);\n\n        _creditNativeFee(oracleAddress, oracleFee);\n    }\n\n    function _handleProtocolFee(uint _relayerFee, uint _oracleFee, address _ua, address _zroPaymentAddress) internal returns (uint protocolNativeFee) {\n        // if no ZRO token or not specifying a payment address, pay in native token\n        bool payInNative = _zroPaymentAddress == address(0x0) || address(layerZeroToken) == address(0x0);\n        uint protocolFee = treasuryContract.getFees(!payInNative, _relayerFee, _oracleFee);\n\n        if (protocolFee \u003e 0) {\n            if (payInNative) {\n                address treasuryAddress = address(treasuryContract);\n                _creditNativeFee(treasuryAddress, protocolFee);\n                protocolNativeFee = protocolFee;\n            } else {\n                // zro payment address must equal the ua or the tx.origin otherwise the transaction reverts\n                require(_zroPaymentAddress == _ua || _zroPaymentAddress == tx.origin, \"LayerZero: must be paid by sender or origin\");\n\n                // transfer the LayerZero token to this contract from the payee\n                layerZeroToken.safeTransferFrom(_zroPaymentAddress, address(this), protocolFee);\n\n                treasuryZROFees = treasuryZROFees.add(protocolFee);\n            }\n        }\n    }\n\n    function _creditNativeFee(address _receiver, uint _amount) internal {\n        nativeFees[_receiver] = nativeFees[_receiver].add(_amount);\n    }\n\n    // Can be called by any address to update a block header\n    // can only upload new block data or the same block data with more confirmations\n    function updateHash(uint16 _srcChainId, bytes32 _lookupHash, uint _confirmations, bytes32 _blockData) external override {\n        uint storedConfirmations = hashLookup[msg.sender][_srcChainId][_lookupHash][_blockData];\n\n        // if it has a record, requires a larger confirmation.\n        require(storedConfirmations \u003c _confirmations, \"LayerZero: oracle data can only update if it has more confirmations\");\n\n        // set the new information into storage\n        hashLookup[msg.sender][_srcChainId][_lookupHash][_blockData] = _confirmations;\n\n        emit HashReceived(_srcChainId, msg.sender, _lookupHash, _blockData, _confirmations);\n    }\n\n    //----------------------------------------------------------------------------------\n    // Other Library Interfaces\n\n    // default to DEFAULT setting if ZERO value\n    function getAppConfig(uint16 _remoteChainId, address _ua) external view override returns (ApplicationConfiguration memory) {\n        return _getAppConfig(_remoteChainId, _ua);\n    }\n\n    function _getAppConfig(uint16 _remoteChainId, address _ua) internal view returns (ApplicationConfiguration memory) {\n        ApplicationConfiguration memory config = appConfig[_ua][_remoteChainId];\n        ApplicationConfiguration storage defaultConfig = defaultAppConfig[_remoteChainId];\n\n        if (config.inboundProofLibraryVersion == 0) {\n            config.inboundProofLibraryVersion = defaultConfig.inboundProofLibraryVersion;\n        }\n\n        if (config.inboundBlockConfirmations == 0) {\n            config.inboundBlockConfirmations = defaultConfig.inboundBlockConfirmations;\n        }\n\n        if (config.relayer == address(0x0)) {\n            config.relayer = defaultConfig.relayer;\n        }\n\n        if (config.outboundProofType == 0) {\n            config.outboundProofType = defaultConfig.outboundProofType;\n        }\n\n        if (config.outboundBlockConfirmations == 0) {\n            config.outboundBlockConfirmations = defaultConfig.outboundBlockConfirmations;\n        }\n\n        if (config.oracle == address(0x0)) {\n            config.oracle = defaultConfig.oracle;\n        }\n\n        return config;\n    }\n\n    function setConfig(uint16 _remoteChainId, address _ua, uint _configType, bytes calldata _config) external override onlyEndpoint {\n        ApplicationConfiguration storage uaConfig = appConfig[_ua][_remoteChainId];\n        if (_configType == CONFIG_TYPE_INBOUND_PROOF_LIBRARY_VERSION) {\n            uint16 inboundProofLibraryVersion = abi.decode(_config, (uint16));\n            require(inboundProofLibraryVersion \u003c= maxInboundProofLibrary[_remoteChainId], \"LayerZero: invalid inbound proof library version\");\n            uaConfig.inboundProofLibraryVersion = inboundProofLibraryVersion;\n        } else if (_configType == CONFIG_TYPE_INBOUND_BLOCK_CONFIRMATIONS) {\n            uint64 blockConfirmations = abi.decode(_config, (uint64));\n            uaConfig.inboundBlockConfirmations = blockConfirmations;\n        } else if (_configType == CONFIG_TYPE_RELAYER) {\n            address relayer = abi.decode(_config, (address));\n            uaConfig.relayer = relayer;\n        } else if (_configType == CONFIG_TYPE_OUTBOUND_PROOF_TYPE) {\n            uint16 outboundProofType = abi.decode(_config, (uint16));\n            require(supportedOutboundProof[_remoteChainId][outboundProofType] || outboundProofType == 0, \"LayerZero: invalid outbound proof type\");\n            uaConfig.outboundProofType = outboundProofType;\n        } else if (_configType == CONFIG_TYPE_OUTBOUND_BLOCK_CONFIRMATIONS) {\n            uint64 blockConfirmations = abi.decode(_config, (uint64));\n            uaConfig.outboundBlockConfirmations = blockConfirmations;\n        } else if (_configType == CONFIG_TYPE_ORACLE) {\n            address oracle = abi.decode(_config, (address));\n            uaConfig.oracle = oracle;\n        } else {\n            revert(\"LayerZero: Invalid config type\");\n        }\n\n        emit AppConfigUpdated(_ua, _configType, _config);\n    }\n\n    function getConfig(uint16 _remoteChainId, address _ua, uint _configType) external view override returns (bytes memory) {\n        ApplicationConfiguration storage uaConfig = appConfig[_ua][_remoteChainId];\n\n        if (_configType == CONFIG_TYPE_INBOUND_PROOF_LIBRARY_VERSION) {\n            if (uaConfig.inboundProofLibraryVersion == 0) {\n                return abi.encode(defaultAppConfig[_remoteChainId].inboundProofLibraryVersion);\n            }\n            return abi.encode(uaConfig.inboundProofLibraryVersion);\n        } else if (_configType == CONFIG_TYPE_INBOUND_BLOCK_CONFIRMATIONS) {\n            if (uaConfig.inboundBlockConfirmations == 0) {\n                return abi.encode(defaultAppConfig[_remoteChainId].inboundBlockConfirmations);\n            }\n            return abi.encode(uaConfig.inboundBlockConfirmations);\n        } else if (_configType == CONFIG_TYPE_RELAYER) {\n            if (uaConfig.relayer == address(0x0)) {\n                return abi.encode(defaultAppConfig[_remoteChainId].relayer);\n            }\n            return abi.encode(uaConfig.relayer);\n        } else if (_configType == CONFIG_TYPE_OUTBOUND_PROOF_TYPE) {\n            if (uaConfig.outboundProofType == 0) {\n                return abi.encode(defaultAppConfig[_remoteChainId].outboundProofType);\n            }\n            return abi.encode(uaConfig.outboundProofType);\n        } else if (_configType == CONFIG_TYPE_OUTBOUND_BLOCK_CONFIRMATIONS) {\n            if (uaConfig.outboundBlockConfirmations == 0) {\n                return abi.encode(defaultAppConfig[_remoteChainId].outboundBlockConfirmations);\n            }\n            return abi.encode(uaConfig.outboundBlockConfirmations);\n        } else if (_configType == CONFIG_TYPE_ORACLE) {\n            if (uaConfig.oracle == address(0x0)) {\n                return abi.encode(defaultAppConfig[_remoteChainId].oracle);\n            }\n            return abi.encode(uaConfig.oracle);\n        } else {\n            revert(\"LayerZero: Invalid config type\");\n        }\n    }\n\n    // returns the native fee the UA pays to cover fees\n    function estimateFees(uint16 _dstChainId, address _ua, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParams) external view override returns (uint nativeFee, uint zroFee) {\n        ApplicationConfiguration memory uaConfig = _getAppConfig(_dstChainId, _ua);\n\n        // Relayer Fee\n        bytes memory adapterParams;\n        if (_adapterParams.length \u003e 0) {\n            adapterParams = _adapterParams;\n        } else {\n            adapterParams = defaultAdapterParams[_dstChainId][uaConfig.outboundProofType];\n        }\n        uint relayerFee = ILayerZeroRelayerV2(uaConfig.relayer).getFee(_dstChainId, uaConfig.outboundProofType, _ua, _payload.length, adapterParams);\n\n        // Oracle Fee\n        address ua = _ua; // stack too deep\n        uint oracleFee = ILayerZeroOracleV2(uaConfig.oracle).getFee(_dstChainId, uaConfig.outboundProofType, uaConfig.outboundBlockConfirmations, ua);\n\n        // LayerZero Fee\n        uint protocolFee = treasuryContract.getFees(_payInZRO, relayerFee, oracleFee);\n        _payInZRO ? zroFee = protocolFee : nativeFee = protocolFee;\n\n        // return the sum of fees\n        nativeFee = nativeFee.add(relayerFee).add(oracleFee);\n    }\n\n    //---------------------------------------------------------------------------\n    // Claim Fees\n\n    // universal withdraw ZRO token function\n    function withdrawZRO(address _to, uint _amount) external override nonReentrant {\n        require(msg.sender == address(treasuryContract), \"LayerZero: only treasury\");\n        treasuryZROFees = treasuryZROFees.sub(_amount);\n        layerZeroToken.safeTransfer(_to, _amount);\n        emit WithdrawZRO(msg.sender, _to, _amount);\n    }\n\n    // universal withdraw native token function.\n    // the source contract should perform all the authentication control\n    function withdrawNative(address payable _to, uint _amount) external override nonReentrant {\n        require(_to != address(0x0), \"LayerZero: _to cannot be zero address\");\n        nativeFees[msg.sender] = nativeFees[msg.sender].sub(_amount);\n\n        (bool success, ) = _to.call{value: _amount}(\"\");\n        require(success, \"LayerZero: withdraw failed\");\n        emit WithdrawNative(msg.sender, _to, _amount);\n    }\n\n    //---------------------------------------------------------------------------\n    // Owner calls, configuration only.\n    function setLayerZeroToken(address _layerZeroToken) external onlyOwner {\n        require(_layerZeroToken != address(0x0), \"LayerZero: _layerZeroToken cannot be zero address\");\n        layerZeroToken = IERC20(_layerZeroToken);\n        emit SetLayerZeroToken(_layerZeroToken);\n    }\n\n    function setTreasury(address _treasury) external onlyOwner {\n        require(_treasury != address(0x0), \"LayerZero: treasury cannot be zero address\");\n        treasuryContract = ILayerZeroTreasury(_treasury);\n        emit SetTreasury(_treasury);\n    }\n\n    function addInboundProofLibraryForChain(uint16 _chainId, address _library) external onlyOwner {\n        require(_library != address(0x0), \"LayerZero: library cannot be zero address\");\n        uint16 libId = maxInboundProofLibrary[_chainId];\n        require(libId \u003c 65535, \"LayerZero: can not add new library\");\n        maxInboundProofLibrary[_chainId] = ++libId;\n        inboundProofLibrary[_chainId][libId] = _library;\n        emit AddInboundProofLibraryForChain(_chainId, _library);\n    }\n\n    function enableSupportedOutboundProof(uint16 _chainId, uint16 _proofType) external onlyOwner {\n        supportedOutboundProof[_chainId][_proofType] = true;\n        emit EnableSupportedOutboundProof(_chainId, _proofType);\n    }\n\n    function setDefaultConfigForChainId(uint16 _chainId, uint16 _inboundProofLibraryVersion, uint64 _inboundBlockConfirmations, address _relayer, uint16 _outboundProofType, uint64 _outboundBlockConfirmations, address _oracle) external onlyOwner {\n        require(_inboundProofLibraryVersion \u003c= maxInboundProofLibrary[_chainId] \u0026\u0026 _inboundProofLibraryVersion \u003e 0, \"LayerZero: invalid inbound proof library version\");\n        require(_inboundBlockConfirmations \u003e 0, \"LayerZero: invalid inbound block confirmation\");\n        require(_relayer != address(0x0), \"LayerZero: invalid relayer address\");\n        require(supportedOutboundProof[_chainId][_outboundProofType], \"LayerZero: invalid outbound proof type\");\n        require(_outboundBlockConfirmations \u003e 0, \"LayerZero: invalid outbound block confirmation\");\n        require(_oracle != address(0x0), \"LayerZero: invalid oracle address\");\n        defaultAppConfig[_chainId] = ApplicationConfiguration(_inboundProofLibraryVersion, _inboundBlockConfirmations, _relayer, _outboundProofType, _outboundBlockConfirmations, _oracle);\n        emit SetDefaultConfigForChainId(_chainId, _inboundProofLibraryVersion, _inboundBlockConfirmations, _relayer, _outboundProofType, _outboundBlockConfirmations, _oracle);\n    }\n\n    function setDefaultAdapterParamsForChainId(uint16 _chainId, uint16 _proofType, bytes calldata _adapterParams) external onlyOwner {\n        defaultAdapterParams[_chainId][_proofType] = _adapterParams;\n        emit SetDefaultAdapterParamsForChainId(_chainId, _proofType, _adapterParams);\n    }\n\n    function setRemoteUln(uint16 _remoteChainId, bytes32 _remoteUln) external onlyOwner {\n        require(ulnLookup[_remoteChainId] == bytes32(0), \"LayerZero: remote uln already set\");\n        ulnLookup[_remoteChainId] = _remoteUln;\n        emit SetRemoteUln(_remoteChainId, _remoteUln);\n    }\n\n    function setChainAddressSize(uint16 _chainId, uint _size) external onlyOwner {\n        require(chainAddressSizeMap[_chainId] == 0, \"LayerZero: remote chain address size already set\");\n        chainAddressSizeMap[_chainId] = _size;\n        emit SetChainAddressSize(_chainId, _size);\n    }\n\n    //----------------------------------------------------------------------------------\n    // view functions\n\n    function accruedNativeFee(address _address) external view override returns (uint) {\n        return nativeFees[_address];\n    }\n\n    function getOutboundNonce(uint16 _chainId, bytes calldata _path) external view override returns (uint64) {\n        return nonceContract.outboundNonce(_chainId, _path);\n    }\n\n    function _isContract(address addr) internal view returns (bool) {\n        uint size;\n        assembly {\n            size := extcodesize(addr)\n        }\n        return size != 0;\n    }\n}\n"}}

                                    File 5 of 12: VerifierNetwork
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    struct PacketForQuote {
                                        address sender;
                                        uint32 dstEid;
                                        bytes message;
                                    }
                                    struct Packet {
                                        uint64 nonce;
                                        uint32 srcEid;
                                        address sender;
                                        uint32 dstEid;
                                        bytes32 receiver;
                                        bytes32 guid;
                                        bytes message;
                                    }
                                    struct Origin {
                                        uint32 srcEid;
                                        bytes32 sender;
                                        uint64 nonce;
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    import "./IMessageLibManager.sol";
                                    import "./IMessagingComposer.sol";
                                    import "./IMessagingChannel.sol";
                                    import "./IMessagingContext.sol";
                                    import {Origin} from "../MessagingStructs.sol";
                                    struct MessagingParams {
                                        uint32 dstEid;
                                        bytes32 receiver;
                                        bytes message;
                                        bytes options;
                                    }
                                    struct MessagingReceipt {
                                        bytes32 guid;
                                        uint64 nonce;
                                        MessagingFee fee;
                                    }
                                    struct MessagingFee {
                                        uint nativeFee;
                                        uint lzTokenFee;
                                    }
                                    interface ILayerZeroEndpointV2 is IMessageLibManager, IMessagingComposer, IMessagingChannel, IMessagingContext {
                                        event PacketSent(bytes encodedPayload, bytes options, address sendLibrary);
                                        event PacketDelivered(Origin origin, address receiver, bytes32 payloadHash);
                                        event PacketReceived(Origin origin, address receiver);
                                        event LzReceiveFailed(Origin origin, address receiver, bytes reason);
                                        event LayerZeroTokenSet(address token);
                                        function quote(
                                            address _sender,
                                            uint32 _dstEid,
                                            bytes calldata _message,
                                            bool _payInLzToken,
                                            bytes calldata _options
                                        ) external view returns (MessagingFee memory);
                                        function send(
                                            MessagingParams calldata _params,
                                            uint _lzTokenFee,
                                            address payable _refundAddress
                                        ) external payable returns (MessagingReceipt memory);
                                        function sendWithAlt(
                                            MessagingParams calldata _params,
                                            uint _lzTokenFee,
                                            uint _altTokenFee
                                        ) external returns (MessagingReceipt memory);
                                        function deliver(Origin calldata _origin, address _receiver, bytes32 _payloadHash) external;
                                        function deliverable(Origin calldata _origin, address _receiveLib, address _receiver) external view returns (bool);
                                        function lzReceive(
                                            Origin calldata _origin,
                                            address _receiver,
                                            bytes32 _guid,
                                            bytes calldata _message,
                                            bytes calldata _extraData
                                        ) external payable returns (bool, bytes memory);
                                        // oapp can burn messages partially by calling this function with its own business logic if messages are delivered in order
                                        function clear(Origin calldata _origin, bytes32 _guid, bytes calldata _message) external;
                                        function setLayerZeroToken(address _layerZeroToken) external;
                                        function layerZeroToken() external view returns (address);
                                        function altFeeToken() external view returns (address);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
                                    import {MessagingFee, SetConfigParam} from "./ILayerZeroEndpointV2.sol";
                                    import {Packet, PacketForQuote} from "../MessagingStructs.sol";
                                    interface IMessageLib is IERC165 {
                                        function send(
                                            Packet calldata _packet,
                                            bytes calldata _options,
                                            bool _payInLzToken
                                        ) external returns (MessagingFee memory, bytes memory encodedPacket);
                                        function quote(
                                            PacketForQuote calldata _packet,
                                            bool _payInLzToken,
                                            bytes calldata _options
                                        ) external view returns (MessagingFee memory);
                                        function setTreasury(address _treasury) external;
                                        function setConfig(address _oapp, uint32 _eid, SetConfigParam[] calldata _config) external;
                                        function snapshotConfig(uint32[] calldata _eids, address _oapp) external;
                                        function resetConfig(uint32[] calldata _eids, address _oapp) external;
                                        function getConfig(
                                            uint32 _eid,
                                            address _oapp,
                                            uint32 _configType
                                        ) external view returns (bytes memory config, bool isDefault);
                                        function getDefaultConfig(uint32 _eid, uint32 _configType) external view returns (bytes memory);
                                        function isSupportedEid(uint32 _eid) external view returns (bool);
                                        function withdrawFee(address _to, uint _amount) external;
                                        function withdrawLzTokenFee(address _lzToken, address _to, uint _amount) external;
                                        // message libs of same major version are compatible
                                        function version() external view returns (uint64 major, uint8 minor, uint8 endpointVersion);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    struct SetConfigParam {
                                        uint32 configType;
                                        bytes config;
                                    }
                                    interface IMessageLibManager {
                                        struct Timeout {
                                            address lib;
                                            uint expiry;
                                        }
                                        event LibraryRegistered(address newLib);
                                        event DefaultSendLibrarySet(uint32 eid, address newLib);
                                        event DefaultReceiveLibrarySet(uint32 eid, address oldLib, address newLib);
                                        event DefaultReceiveLibraryTimeoutSet(uint32 eid, address oldLib, uint expiry);
                                        event SendLibrarySet(address sender, uint32 eid, address newLib);
                                        event ReceiveLibrarySet(address receiver, uint32 eid, address oldLib, address newLib);
                                        event ReceiveLibraryTimoutSet(address receiver, uint32 eid, address oldLib, uint timeout);
                                        function registerLibrary(address _lib) external;
                                        function isRegisteredLibrary(address _lib) external view returns (bool);
                                        function getRegisteredLibraries() external view returns (address[] memory);
                                        function setDefaultSendLibrary(uint32 _eid, address _newLib) external;
                                        function defaultSendLibrary(uint32 _eid) external view returns (address);
                                        function setDefaultReceiveLibrary(uint32 _eid, address _newLib, uint _timeout) external;
                                        function defaultReceiveLibrary(uint32 _eid) external view returns (address);
                                        function setDefaultReceiveLibraryTimeout(uint32 _eid, address _lib, uint _expiry) external;
                                        function defaultReceiveLibraryTimeout(uint32 _eid) external view returns (address lib, uint expiry);
                                        function defaultConfig(address _lib, uint32 _eid, uint32 _configType) external view returns (bytes memory);
                                        function isSupportedEid(uint32 _eid) external view returns (bool);
                                        /// ------------------- OApp interfaces -------------------
                                        function setSendLibrary(uint32 _eid, address _newLib) external;
                                        function getSendLibrary(address _sender, uint32 _eid) external view returns (address lib);
                                        function isDefaultSendLibrary(address _sender, uint32 _eid) external view returns (bool);
                                        function setReceiveLibrary(uint32 _eid, address _newLib, uint _gracePeriod) external;
                                        function getReceiveLibrary(address _receiver, uint32 _eid) external view returns (address lib, bool isDefault);
                                        function setReceiveLibraryTimeout(uint32 _eid, address _lib, uint _gracePeriod) external;
                                        function receiveLibraryTimeout(address _receiver, uint32 _eid) external view returns (address lib, uint expiry);
                                        function setConfig(address _lib, uint32 _eid, SetConfigParam[] calldata _params) external;
                                        function getConfig(
                                            address _oapp,
                                            address _lib,
                                            uint32 _eid,
                                            uint32 _configType
                                        ) external view returns (bytes memory config, bool isDefault);
                                        function snapshotConfig(address _lib, uint32[] calldata _eids) external;
                                        function resetConfig(address _lib, uint32[] calldata _eids) external;
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface IMessagingChannel {
                                        event InboundNonceSkipped(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce);
                                        function eid() external view returns (uint32);
                                        // this is an emergency function if a message can not be delivered for some reasons
                                        // required to provide _nextNonce to avoid race condition
                                        function skip(uint32 _srcEid, bytes32 _sender, uint64 _nonce) external;
                                        function nextGuid(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (bytes32);
                                        function inboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64);
                                        function outboundNonce(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (uint64);
                                        function inboundPayloadHash(
                                            address _receiver,
                                            uint32 _srcEid,
                                            bytes32 _sender,
                                            uint64 _nonce
                                        ) external view returns (bytes32);
                                        function hasPayloadHash(
                                            address _receiver,
                                            uint32 _srcEid,
                                            bytes32 _sender,
                                            uint64 _nonce
                                        ) external view returns (bool);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface IMessagingComposer {
                                        event ComposedMessageDelivered(address receiver, address composer, bytes32 guid, bytes message);
                                        event ComposedMessageReceived(address receiver, address composer, bytes32 guid);
                                        event LzComposeFailed(address receiver, address composer, bytes32 guid, bytes reason);
                                        function deliverComposedMessage(address _composer, bytes32 _guid, bytes calldata _message) external;
                                        function lzCompose(
                                            address _receiver,
                                            address _composer,
                                            bytes32 _guid,
                                            bytes calldata _message,
                                            bytes calldata _extraData
                                        ) external payable returns (bool, bytes memory);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface IMessagingContext {
                                        function isSendingMessage() external view returns (bool);
                                        function getSendContext() external view returns (uint32, address);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity ^0.8.0;
                                    library Errors {
                                        // Invalid Argument (http: 400)
                                        string internal constant INVALID_ARGUMENT = "LZ10000";
                                        string internal constant ONLY_REGISTERED = "LZ10001";
                                        string internal constant ONLY_REGISTERED_OR_DEFAULT = "LZ10002";
                                        string internal constant INVALID_AMOUNT = "LZ10003";
                                        string internal constant INVALID_NONCE = "LZ10004";
                                        string internal constant SAME_VALUE = "LZ10005";
                                        string internal constant UNSORTED = "LZ10006";
                                        string internal constant INVALID_VERSION = "LZ10007";
                                        string internal constant INVALID_EID = "LZ10008";
                                        string internal constant INVALID_SIZE = "LZ10009";
                                        string internal constant ONLY_NON_DEFAULT = "LZ10010";
                                        string internal constant INVALID_VERIFIERS = "LZ10011";
                                        string internal constant INVALID_WORKER_ID = "LZ10012";
                                        string internal constant DUPLICATED_OPTION = "LZ10013";
                                        string internal constant INVALID_LEGACY_OPTION = "LZ10014";
                                        string internal constant INVALID_VERIFIER_OPTION = "LZ10015";
                                        string internal constant INVALID_WORKER_OPTIONS = "LZ10016";
                                        string internal constant INVALID_EXECUTOR_OPTION = "LZ10017";
                                        string internal constant INVALID_ADDRESS = "LZ10018";
                                        // Out of Range (http: 400)
                                        string internal constant OUT_OF_RANGE = "LZ20000";
                                        // Invalid State (http: 400)
                                        string internal constant INVALID_STATE = "LZ30000";
                                        string internal constant SEND_REENTRANCY = "LZ30001";
                                        string internal constant RECEIVE_REENTRANCY = "LZ30002";
                                        string internal constant COMPOSE_REENTRANCY = "LZ30003";
                                        // Permission Denied (http: 403)
                                        string internal constant PERMISSION_DENIED = "LZ50000";
                                        // Not Found (http: 404)
                                        string internal constant NOT_FOUND = "LZ60000";
                                        // Already Exists (http: 409)
                                        string internal constant ALREADY_EXISTS = "LZ80000";
                                        // Not Implemented (http: 501)
                                        string internal constant NOT_IMPLEMENTED = "LZC0000";
                                        string internal constant UNSUPPORTED_INTERFACE = "LZC0001";
                                        string internal constant UNSUPPORTED_OPTION_TYPE = "LZC0002";
                                        // Unavailable (http: 503)
                                        string internal constant UNAVAILABLE = "LZD0000";
                                        string internal constant NATIVE_COIN_UNAVAILABLE = "LZD0001";
                                        string internal constant TOKEN_UNAVAILABLE = "LZD0002";
                                        string internal constant DEFAULT_LIBRARY_UNAVAILABLE = "LZD0003";
                                        string internal constant VERIFIERS_UNAVAILABLE = "LZD0004";
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface ILayerZeroUltraLightNodeV2 {
                                        // Relayer functions
                                        function validateTransactionProof(
                                            uint16 _srcChainId,
                                            address _dstAddress,
                                            uint _gasLimit,
                                            bytes32 _lookupHash,
                                            bytes32 _blockData,
                                            bytes calldata _transactionProof
                                        ) external;
                                        // an Oracle delivers the block data using updateHash()
                                        function updateHash(uint16 _srcChainId, bytes32 _lookupHash, uint _confirmations, bytes32 _blockData) external;
                                        // can only withdraw the receivable of the msg.sender
                                        function withdrawNative(address payable _to, uint _amount) external;
                                        function withdrawZRO(address _to, uint _amount) external;
                                        // view functions
                                        function getAppConfig(
                                            uint16 _remoteChainId,
                                            address _userApplicationAddress
                                        ) external view returns (ApplicationConfiguration memory);
                                        function accruedNativeFee(address _address) external view returns (uint);
                                        struct ApplicationConfiguration {
                                            uint16 inboundProofLibraryVersion;
                                            uint64 inboundBlockConfirmations;
                                            address relayer;
                                            uint16 outboundProofType;
                                            uint64 outboundBlockConfirmations;
                                            address oracle;
                                        }
                                        event HashReceived(
                                            uint16 indexed srcChainId,
                                            address indexed oracle,
                                            bytes32 lookupHash,
                                            bytes32 blockData,
                                            uint confirmations
                                        );
                                        event RelayerParams(bytes adapterParams, uint16 outboundProofType);
                                        event Packet(bytes payload);
                                        event InvalidDst(
                                            uint16 indexed srcChainId,
                                            bytes srcAddress,
                                            address indexed dstAddress,
                                            uint64 nonce,
                                            bytes32 payloadHash
                                        );
                                        event PacketReceived(
                                            uint16 indexed srcChainId,
                                            bytes srcAddress,
                                            address indexed dstAddress,
                                            uint64 nonce,
                                            bytes32 payloadHash
                                        );
                                        event AppConfigUpdated(address indexed userApplication, uint indexed configType, bytes newConfig);
                                        event AddInboundProofLibraryForChain(uint16 indexed chainId, address lib);
                                        event EnableSupportedOutboundProof(uint16 indexed chainId, uint16 proofType);
                                        event SetChainAddressSize(uint16 indexed chainId, uint size);
                                        event SetDefaultConfigForChainId(
                                            uint16 indexed chainId,
                                            uint16 inboundProofLib,
                                            uint64 inboundBlockConfirm,
                                            address relayer,
                                            uint16 outboundProofType,
                                            uint64 outboundBlockConfirm,
                                            address oracle
                                        );
                                        event SetDefaultAdapterParamsForChainId(uint16 indexed chainId, uint16 indexed proofType, bytes adapterParams);
                                        event SetLayerZeroToken(address indexed tokenAddress);
                                        event SetRemoteUln(uint16 indexed chainId, bytes32 uln);
                                        event SetTreasury(address indexed treasuryAddress);
                                        event WithdrawZRO(address indexed msgSender, address indexed to, uint amount);
                                        event WithdrawNative(address indexed msgSender, address indexed to, uint amount);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.9.0) (access/AccessControl.sol)
                                    pragma solidity ^0.8.0;
                                    import "./IAccessControl.sol";
                                    import "../utils/Context.sol";
                                    import "../utils/Strings.sol";
                                    import "../utils/introspection/ERC165.sol";
                                    /**
                                     * @dev Contract module that allows children to implement role-based access
                                     * control mechanisms. This is a lightweight version that doesn't allow enumerating role
                                     * members except through off-chain means by accessing the contract event logs. Some
                                     * applications may benefit from on-chain enumerability, for those cases see
                                     * {AccessControlEnumerable}.
                                     *
                                     * Roles are referred to by their `bytes32` identifier. These should be exposed
                                     * in the external API and be unique. The best way to achieve this is by
                                     * using `public constant` hash digests:
                                     *
                                     * ```solidity
                                     * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
                                     * ```
                                     *
                                     * Roles can be used to represent a set of permissions. To restrict access to a
                                     * function call, use {hasRole}:
                                     *
                                     * ```solidity
                                     * function foo() public {
                                     *     require(hasRole(MY_ROLE, msg.sender));
                                     *     ...
                                     * }
                                     * ```
                                     *
                                     * Roles can be granted and revoked dynamically via the {grantRole} and
                                     * {revokeRole} functions. Each role has an associated admin role, and only
                                     * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
                                     *
                                     * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
                                     * that only accounts with this role will be able to grant or revoke other
                                     * roles. More complex role relationships can be created by using
                                     * {_setRoleAdmin}.
                                     *
                                     * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
                                     * grant and revoke this role. Extra precautions should be taken to secure
                                     * accounts that have been granted it. We recommend using {AccessControlDefaultAdminRules}
                                     * to enforce additional security measures for this role.
                                     */
                                    abstract contract AccessControl is Context, IAccessControl, ERC165 {
                                        struct RoleData {
                                            mapping(address => bool) members;
                                            bytes32 adminRole;
                                        }
                                        mapping(bytes32 => RoleData) private _roles;
                                        bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
                                        /**
                                         * @dev Modifier that checks that an account has a specific role. Reverts
                                         * with a standardized message including the required role.
                                         *
                                         * The format of the revert reason is given by the following regular expression:
                                         *
                                         *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
                                         *
                                         * _Available since v4.1._
                                         */
                                        modifier onlyRole(bytes32 role) {
                                            _checkRole(role);
                                            _;
                                        }
                                        /**
                                         * @dev See {IERC165-supportsInterface}.
                                         */
                                        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                                            return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
                                        }
                                        /**
                                         * @dev Returns `true` if `account` has been granted `role`.
                                         */
                                        function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
                                            return _roles[role].members[account];
                                        }
                                        /**
                                         * @dev Revert with a standard message if `_msgSender()` is missing `role`.
                                         * Overriding this function changes the behavior of the {onlyRole} modifier.
                                         *
                                         * Format of the revert message is described in {_checkRole}.
                                         *
                                         * _Available since v4.6._
                                         */
                                        function _checkRole(bytes32 role) internal view virtual {
                                            _checkRole(role, _msgSender());
                                        }
                                        /**
                                         * @dev Revert with a standard message if `account` is missing `role`.
                                         *
                                         * The format of the revert reason is given by the following regular expression:
                                         *
                                         *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
                                         */
                                        function _checkRole(bytes32 role, address account) internal view virtual {
                                            if (!hasRole(role, account)) {
                                                revert(
                                                    string(
                                                        abi.encodePacked(
                                                            "AccessControl: account ",
                                                            Strings.toHexString(account),
                                                            " is missing role ",
                                                            Strings.toHexString(uint256(role), 32)
                                                        )
                                                    )
                                                );
                                            }
                                        }
                                        /**
                                         * @dev Returns the admin role that controls `role`. See {grantRole} and
                                         * {revokeRole}.
                                         *
                                         * To change a role's admin, use {_setRoleAdmin}.
                                         */
                                        function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
                                            return _roles[role].adminRole;
                                        }
                                        /**
                                         * @dev Grants `role` to `account`.
                                         *
                                         * If `account` had not been already granted `role`, emits a {RoleGranted}
                                         * event.
                                         *
                                         * Requirements:
                                         *
                                         * - the caller must have ``role``'s admin role.
                                         *
                                         * May emit a {RoleGranted} event.
                                         */
                                        function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                                            _grantRole(role, account);
                                        }
                                        /**
                                         * @dev Revokes `role` from `account`.
                                         *
                                         * If `account` had been granted `role`, emits a {RoleRevoked} event.
                                         *
                                         * Requirements:
                                         *
                                         * - the caller must have ``role``'s admin role.
                                         *
                                         * May emit a {RoleRevoked} event.
                                         */
                                        function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                                            _revokeRole(role, account);
                                        }
                                        /**
                                         * @dev Revokes `role` from the calling account.
                                         *
                                         * Roles are often managed via {grantRole} and {revokeRole}: this function's
                                         * purpose is to provide a mechanism for accounts to lose their privileges
                                         * if they are compromised (such as when a trusted device is misplaced).
                                         *
                                         * If the calling account had been revoked `role`, emits a {RoleRevoked}
                                         * event.
                                         *
                                         * Requirements:
                                         *
                                         * - the caller must be `account`.
                                         *
                                         * May emit a {RoleRevoked} event.
                                         */
                                        function renounceRole(bytes32 role, address account) public virtual override {
                                            require(account == _msgSender(), "AccessControl: can only renounce roles for self");
                                            _revokeRole(role, account);
                                        }
                                        /**
                                         * @dev Grants `role` to `account`.
                                         *
                                         * If `account` had not been already granted `role`, emits a {RoleGranted}
                                         * event. Note that unlike {grantRole}, this function doesn't perform any
                                         * checks on the calling account.
                                         *
                                         * May emit a {RoleGranted} event.
                                         *
                                         * [WARNING]
                                         * ====
                                         * This function should only be called from the constructor when setting
                                         * up the initial roles for the system.
                                         *
                                         * Using this function in any other way is effectively circumventing the admin
                                         * system imposed by {AccessControl}.
                                         * ====
                                         *
                                         * NOTE: This function is deprecated in favor of {_grantRole}.
                                         */
                                        function _setupRole(bytes32 role, address account) internal virtual {
                                            _grantRole(role, account);
                                        }
                                        /**
                                         * @dev Sets `adminRole` as ``role``'s admin role.
                                         *
                                         * Emits a {RoleAdminChanged} event.
                                         */
                                        function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
                                            bytes32 previousAdminRole = getRoleAdmin(role);
                                            _roles[role].adminRole = adminRole;
                                            emit RoleAdminChanged(role, previousAdminRole, adminRole);
                                        }
                                        /**
                                         * @dev Grants `role` to `account`.
                                         *
                                         * Internal function without access restriction.
                                         *
                                         * May emit a {RoleGranted} event.
                                         */
                                        function _grantRole(bytes32 role, address account) internal virtual {
                                            if (!hasRole(role, account)) {
                                                _roles[role].members[account] = true;
                                                emit RoleGranted(role, account, _msgSender());
                                            }
                                        }
                                        /**
                                         * @dev Revokes `role` from `account`.
                                         *
                                         * Internal function without access restriction.
                                         *
                                         * May emit a {RoleRevoked} event.
                                         */
                                        function _revokeRole(bytes32 role, address account) internal virtual {
                                            if (hasRole(role, account)) {
                                                _roles[role].members[account] = false;
                                                emit RoleRevoked(role, account, _msgSender());
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev External interface of AccessControl declared to support ERC165 detection.
                                     */
                                    interface IAccessControl {
                                        /**
                                         * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
                                         *
                                         * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
                                         * {RoleAdminChanged} not being emitted signaling this.
                                         *
                                         * _Available since v3.1._
                                         */
                                        event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
                                        /**
                                         * @dev Emitted when `account` is granted `role`.
                                         *
                                         * `sender` is the account that originated the contract call, an admin role
                                         * bearer except when using {AccessControl-_setupRole}.
                                         */
                                        event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
                                        /**
                                         * @dev Emitted when `account` is revoked `role`.
                                         *
                                         * `sender` is the account that originated the contract call:
                                         *   - if using `revokeRole`, it is the admin role bearer
                                         *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
                                         */
                                        event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
                                        /**
                                         * @dev Returns `true` if `account` has been granted `role`.
                                         */
                                        function hasRole(bytes32 role, address account) external view returns (bool);
                                        /**
                                         * @dev Returns the admin role that controls `role`. See {grantRole} and
                                         * {revokeRole}.
                                         *
                                         * To change a role's admin, use {AccessControl-_setRoleAdmin}.
                                         */
                                        function getRoleAdmin(bytes32 role) external view returns (bytes32);
                                        /**
                                         * @dev Grants `role` to `account`.
                                         *
                                         * If `account` had not been already granted `role`, emits a {RoleGranted}
                                         * event.
                                         *
                                         * Requirements:
                                         *
                                         * - the caller must have ``role``'s admin role.
                                         */
                                        function grantRole(bytes32 role, address account) external;
                                        /**
                                         * @dev Revokes `role` from `account`.
                                         *
                                         * If `account` had been granted `role`, emits a {RoleRevoked} event.
                                         *
                                         * Requirements:
                                         *
                                         * - the caller must have ``role``'s admin role.
                                         */
                                        function revokeRole(bytes32 role, address account) external;
                                        /**
                                         * @dev Revokes `role` from the calling account.
                                         *
                                         * Roles are often managed via {grantRole} and {revokeRole}: this function's
                                         * purpose is to provide a mechanism for accounts to lose their privileges
                                         * if they are compromised (such as when a trusted device is misplaced).
                                         *
                                         * If the calling account had been granted `role`, emits a {RoleRevoked}
                                         * event.
                                         *
                                         * Requirements:
                                         *
                                         * - the caller must be `account`.
                                         */
                                        function renounceRole(bytes32 role, address account) external;
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.9.0) (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 Throws if called by any account other than the owner.
                                         */
                                        modifier onlyOwner() {
                                            _checkOwner();
                                            _;
                                        }
                                        /**
                                         * @dev Returns the address of the current owner.
                                         */
                                        function owner() public view virtual returns (address) {
                                            return _owner;
                                        }
                                        /**
                                         * @dev Throws if the sender is not the owner.
                                         */
                                        function _checkOwner() internal view virtual {
                                            require(owner() == _msgSender(), "Ownable: caller is not the owner");
                                        }
                                        /**
                                         * @dev Leaves the contract without owner. It will not be possible to call
                                         * `onlyOwner` functions. Can only be called by the current owner.
                                         *
                                         * NOTE: Renouncing ownership will leave the contract without an owner,
                                         * thereby disabling 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 (last updated v4.7.0) (security/Pausable.sol)
                                    pragma solidity ^0.8.0;
                                    import "../utils/Context.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 Pausable is Context {
                                        /**
                                         * @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.
                                         */
                                        constructor() {
                                            _paused = false;
                                        }
                                        /**
                                         * @dev Modifier to make a function callable only when the contract is not paused.
                                         *
                                         * Requirements:
                                         *
                                         * - The contract must not be paused.
                                         */
                                        modifier whenNotPaused() {
                                            _requireNotPaused();
                                            _;
                                        }
                                        /**
                                         * @dev Modifier to make a function callable only when the contract is paused.
                                         *
                                         * Requirements:
                                         *
                                         * - The contract must be paused.
                                         */
                                        modifier whenPaused() {
                                            _requirePaused();
                                            _;
                                        }
                                        /**
                                         * @dev Returns true if the contract is paused, and false otherwise.
                                         */
                                        function paused() public view virtual returns (bool) {
                                            return _paused;
                                        }
                                        /**
                                         * @dev Throws if the contract is paused.
                                         */
                                        function _requireNotPaused() internal view virtual {
                                            require(!paused(), "Pausable: paused");
                                        }
                                        /**
                                         * @dev Throws if the contract is not paused.
                                         */
                                        function _requirePaused() internal view virtual {
                                            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());
                                        }
                                    }
                                    // 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;
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
                                    pragma solidity ^0.8.0;
                                    import "./math/Math.sol";
                                    import "./math/SignedMath.sol";
                                    /**
                                     * @dev String operations.
                                     */
                                    library Strings {
                                        bytes16 private constant _SYMBOLS = "0123456789abcdef";
                                        uint8 private constant _ADDRESS_LENGTH = 20;
                                        /**
                                         * @dev Converts a `uint256` to its ASCII `string` decimal representation.
                                         */
                                        function toString(uint256 value) internal pure returns (string memory) {
                                            unchecked {
                                                uint256 length = Math.log10(value) + 1;
                                                string memory buffer = new string(length);
                                                uint256 ptr;
                                                /// @solidity memory-safe-assembly
                                                assembly {
                                                    ptr := add(buffer, add(32, length))
                                                }
                                                while (true) {
                                                    ptr--;
                                                    /// @solidity memory-safe-assembly
                                                    assembly {
                                                        mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                                                    }
                                                    value /= 10;
                                                    if (value == 0) break;
                                                }
                                                return buffer;
                                            }
                                        }
                                        /**
                                         * @dev Converts a `int256` to its ASCII `string` decimal representation.
                                         */
                                        function toString(int256 value) internal pure returns (string memory) {
                                            return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
                                        }
                                        /**
                                         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
                                         */
                                        function toHexString(uint256 value) internal pure returns (string memory) {
                                            unchecked {
                                                return toHexString(value, Math.log256(value) + 1);
                                            }
                                        }
                                        /**
                                         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
                                         */
                                        function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
                                            bytes memory buffer = new bytes(2 * length + 2);
                                            buffer[0] = "0";
                                            buffer[1] = "x";
                                            for (uint256 i = 2 * length + 1; i > 1; --i) {
                                                buffer[i] = _SYMBOLS[value & 0xf];
                                                value >>= 4;
                                            }
                                            require(value == 0, "Strings: hex length insufficient");
                                            return string(buffer);
                                        }
                                        /**
                                         * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
                                         */
                                        function toHexString(address addr) internal pure returns (string memory) {
                                            return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
                                        }
                                        /**
                                         * @dev Returns true if the two strings are equal.
                                         */
                                        function equal(string memory a, string memory b) internal pure returns (bool) {
                                            return keccak256(bytes(a)) == keccak256(bytes(b));
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.9.0) (utils/cryptography/ECDSA.sol)
                                    pragma solidity ^0.8.0;
                                    import "../Strings.sol";
                                    /**
                                     * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
                                     *
                                     * These functions can be used to verify that a message was signed by the holder
                                     * of the private keys of a given address.
                                     */
                                    library ECDSA {
                                        enum RecoverError {
                                            NoError,
                                            InvalidSignature,
                                            InvalidSignatureLength,
                                            InvalidSignatureS,
                                            InvalidSignatureV // Deprecated in v4.8
                                        }
                                        function _throwError(RecoverError error) private pure {
                                            if (error == RecoverError.NoError) {
                                                return; // no error: do nothing
                                            } else if (error == RecoverError.InvalidSignature) {
                                                revert("ECDSA: invalid signature");
                                            } else if (error == RecoverError.InvalidSignatureLength) {
                                                revert("ECDSA: invalid signature length");
                                            } else if (error == RecoverError.InvalidSignatureS) {
                                                revert("ECDSA: invalid signature 's' value");
                                            }
                                        }
                                        /**
                                         * @dev Returns the address that signed a hashed message (`hash`) with
                                         * `signature` or error string. This address can then be used for verification purposes.
                                         *
                                         * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
                                         * this function rejects them by requiring the `s` value to be in the lower
                                         * half order, and the `v` value to be either 27 or 28.
                                         *
                                         * IMPORTANT: `hash` _must_ be the result of a hash operation for the
                                         * verification to be secure: it is possible to craft signatures that
                                         * recover to arbitrary addresses for non-hashed data. A safe way to ensure
                                         * this is by receiving a hash of the original message (which may otherwise
                                         * be too long), and then calling {toEthSignedMessageHash} on it.
                                         *
                                         * Documentation for signature generation:
                                         * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
                                         * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
                                         *
                                         * _Available since v4.3._
                                         */
                                        function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
                                            if (signature.length == 65) {
                                                bytes32 r;
                                                bytes32 s;
                                                uint8 v;
                                                // ecrecover takes the signature parameters, and the only way to get them
                                                // currently is to use assembly.
                                                /// @solidity memory-safe-assembly
                                                assembly {
                                                    r := mload(add(signature, 0x20))
                                                    s := mload(add(signature, 0x40))
                                                    v := byte(0, mload(add(signature, 0x60)))
                                                }
                                                return tryRecover(hash, v, r, s);
                                            } else {
                                                return (address(0), RecoverError.InvalidSignatureLength);
                                            }
                                        }
                                        /**
                                         * @dev Returns the address that signed a hashed message (`hash`) with
                                         * `signature`. This address can then be used for verification purposes.
                                         *
                                         * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
                                         * this function rejects them by requiring the `s` value to be in the lower
                                         * half order, and the `v` value to be either 27 or 28.
                                         *
                                         * IMPORTANT: `hash` _must_ be the result of a hash operation for the
                                         * verification to be secure: it is possible to craft signatures that
                                         * recover to arbitrary addresses for non-hashed data. A safe way to ensure
                                         * this is by receiving a hash of the original message (which may otherwise
                                         * be too long), and then calling {toEthSignedMessageHash} on it.
                                         */
                                        function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
                                            (address recovered, RecoverError error) = tryRecover(hash, signature);
                                            _throwError(error);
                                            return recovered;
                                        }
                                        /**
                                         * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
                                         *
                                         * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
                                         *
                                         * _Available since v4.3._
                                         */
                                        function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError) {
                                            bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
                                            uint8 v = uint8((uint256(vs) >> 255) + 27);
                                            return tryRecover(hash, v, r, s);
                                        }
                                        /**
                                         * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
                                         *
                                         * _Available since v4.2._
                                         */
                                        function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
                                            (address recovered, RecoverError error) = tryRecover(hash, r, vs);
                                            _throwError(error);
                                            return recovered;
                                        }
                                        /**
                                         * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
                                         * `r` and `s` signature fields separately.
                                         *
                                         * _Available since v4.3._
                                         */
                                        function tryRecover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address, RecoverError) {
                                            // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
                                            // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
                                            // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
                                            // signatures from current libraries generate a unique signature with an s-value in the lower half order.
                                            //
                                            // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
                                            // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
                                            // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
                                            // these malleable signatures as well.
                                            if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
                                                return (address(0), RecoverError.InvalidSignatureS);
                                            }
                                            // If the signature is valid (and not malleable), return the signer address
                                            address signer = ecrecover(hash, v, r, s);
                                            if (signer == address(0)) {
                                                return (address(0), RecoverError.InvalidSignature);
                                            }
                                            return (signer, RecoverError.NoError);
                                        }
                                        /**
                                         * @dev Overload of {ECDSA-recover} that receives the `v`,
                                         * `r` and `s` signature fields separately.
                                         */
                                        function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
                                            (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
                                            _throwError(error);
                                            return recovered;
                                        }
                                        /**
                                         * @dev Returns an Ethereum Signed Message, created from a `hash`. This
                                         * produces hash corresponding to the one signed with the
                                         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
                                         * JSON-RPC method as part of EIP-191.
                                         *
                                         * See {recover}.
                                         */
                                        function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32 message) {
                                            // 32 is the length in bytes of hash,
                                            // enforced by the type signature above
                                            /// @solidity memory-safe-assembly
                                            assembly {
                                                mstore(0x00, "\\x19Ethereum Signed Message:\
                                    32")
                                                mstore(0x1c, hash)
                                                message := keccak256(0x00, 0x3c)
                                            }
                                        }
                                        /**
                                         * @dev Returns an Ethereum Signed Message, created from `s`. This
                                         * produces hash corresponding to the one signed with the
                                         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
                                         * JSON-RPC method as part of EIP-191.
                                         *
                                         * See {recover}.
                                         */
                                        function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
                                            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
                                    ", Strings.toString(s.length), s));
                                        }
                                        /**
                                         * @dev Returns an Ethereum Signed Typed Data, created from a
                                         * `domainSeparator` and a `structHash`. This produces hash corresponding
                                         * to the one signed with the
                                         * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
                                         * JSON-RPC method as part of EIP-712.
                                         *
                                         * See {recover}.
                                         */
                                        function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32 data) {
                                            /// @solidity memory-safe-assembly
                                            assembly {
                                                let ptr := mload(0x40)
                                                mstore(ptr, "\\x19\\x01")
                                                mstore(add(ptr, 0x02), domainSeparator)
                                                mstore(add(ptr, 0x22), structHash)
                                                data := keccak256(ptr, 0x42)
                                            }
                                        }
                                        /**
                                         * @dev Returns an Ethereum Signed Data with intended validator, created from a
                                         * `validator` and `data` according to the version 0 of EIP-191.
                                         *
                                         * See {recover}.
                                         */
                                        function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
                                            return keccak256(abi.encodePacked("\\x19\\x00", validator, data));
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
                                    pragma solidity ^0.8.0;
                                    import "./IERC165.sol";
                                    /**
                                     * @dev Implementation of the {IERC165} interface.
                                     *
                                     * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
                                     * for the additional interface id that will be supported. For example:
                                     *
                                     * ```solidity
                                     * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                                     *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
                                     * }
                                     * ```
                                     *
                                     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
                                     */
                                    abstract contract ERC165 is IERC165 {
                                        /**
                                         * @dev See {IERC165-supportsInterface}.
                                         */
                                        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                                            return interfaceId == type(IERC165).interfaceId;
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev Interface of the ERC165 standard, as defined in the
                                     * https://eips.ethereum.org/EIPS/eip-165[EIP].
                                     *
                                     * Implementers can declare support of contract interfaces, which can then be
                                     * queried by others ({ERC165Checker}).
                                     *
                                     * For an implementation, see {ERC165}.
                                     */
                                    interface IERC165 {
                                        /**
                                         * @dev Returns true if this contract implements the interface defined by
                                         * `interfaceId`. See the corresponding
                                         * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                                         * to learn more about how these ids are created.
                                         *
                                         * This function call must use less than 30 000 gas.
                                         */
                                        function supportsInterface(bytes4 interfaceId) external view returns (bool);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev Standard math utilities missing in the Solidity language.
                                     */
                                    library Math {
                                        enum Rounding {
                                            Down, // Toward negative infinity
                                            Up, // Toward infinity
                                            Zero // Toward zero
                                        }
                                        /**
                                         * @dev Returns the largest of two numbers.
                                         */
                                        function max(uint256 a, uint256 b) internal pure returns (uint256) {
                                            return a > b ? a : b;
                                        }
                                        /**
                                         * @dev Returns the smallest of two numbers.
                                         */
                                        function min(uint256 a, uint256 b) internal pure returns (uint256) {
                                            return a < b ? a : b;
                                        }
                                        /**
                                         * @dev Returns the average of two numbers. The result is rounded towards
                                         * zero.
                                         */
                                        function average(uint256 a, uint256 b) internal pure returns (uint256) {
                                            // (a + b) / 2 can overflow.
                                            return (a & b) + (a ^ b) / 2;
                                        }
                                        /**
                                         * @dev Returns the ceiling of the division of two numbers.
                                         *
                                         * This differs from standard division with `/` in that it rounds up instead
                                         * of rounding down.
                                         */
                                        function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
                                            // (a + b - 1) / b can overflow on addition, so we distribute.
                                            return a == 0 ? 0 : (a - 1) / b + 1;
                                        }
                                        /**
                                         * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
                                         * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
                                         * with further edits by Uniswap Labs also under MIT license.
                                         */
                                        function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
                                            unchecked {
                                                // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
                                                // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
                                                // variables such that product = prod1 * 2^256 + prod0.
                                                uint256 prod0; // Least significant 256 bits of the product
                                                uint256 prod1; // Most significant 256 bits of the product
                                                assembly {
                                                    let mm := mulmod(x, y, not(0))
                                                    prod0 := mul(x, y)
                                                    prod1 := sub(sub(mm, prod0), lt(mm, prod0))
                                                }
                                                // Handle non-overflow cases, 256 by 256 division.
                                                if (prod1 == 0) {
                                                    // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                                                    // The surrounding unchecked block does not change this fact.
                                                    // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                                                    return prod0 / denominator;
                                                }
                                                // Make sure the result is less than 2^256. Also prevents denominator == 0.
                                                require(denominator > prod1, "Math: mulDiv overflow");
                                                ///////////////////////////////////////////////
                                                // 512 by 256 division.
                                                ///////////////////////////////////////////////
                                                // Make division exact by subtracting the remainder from [prod1 prod0].
                                                uint256 remainder;
                                                assembly {
                                                    // Compute remainder using mulmod.
                                                    remainder := mulmod(x, y, denominator)
                                                    // Subtract 256 bit number from 512 bit number.
                                                    prod1 := sub(prod1, gt(remainder, prod0))
                                                    prod0 := sub(prod0, remainder)
                                                }
                                                // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
                                                // See https://cs.stackexchange.com/q/138556/92363.
                                                // Does not overflow because the denominator cannot be zero at this stage in the function.
                                                uint256 twos = denominator & (~denominator + 1);
                                                assembly {
                                                    // Divide denominator by twos.
                                                    denominator := div(denominator, twos)
                                                    // Divide [prod1 prod0] by twos.
                                                    prod0 := div(prod0, twos)
                                                    // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                                                    twos := add(div(sub(0, twos), twos), 1)
                                                }
                                                // Shift in bits from prod1 into prod0.
                                                prod0 |= prod1 * twos;
                                                // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
                                                // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
                                                // four bits. That is, denominator * inv = 1 mod 2^4.
                                                uint256 inverse = (3 * denominator) ^ 2;
                                                // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
                                                // in modular arithmetic, doubling the correct bits in each step.
                                                inverse *= 2 - denominator * inverse; // inverse mod 2^8
                                                inverse *= 2 - denominator * inverse; // inverse mod 2^16
                                                inverse *= 2 - denominator * inverse; // inverse mod 2^32
                                                inverse *= 2 - denominator * inverse; // inverse mod 2^64
                                                inverse *= 2 - denominator * inverse; // inverse mod 2^128
                                                inverse *= 2 - denominator * inverse; // inverse mod 2^256
                                                // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
                                                // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
                                                // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
                                                // is no longer required.
                                                result = prod0 * inverse;
                                                return result;
                                            }
                                        }
                                        /**
                                         * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
                                         */
                                        function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
                                            uint256 result = mulDiv(x, y, denominator);
                                            if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
                                                result += 1;
                                            }
                                            return result;
                                        }
                                        /**
                                         * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
                                         *
                                         * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
                                         */
                                        function sqrt(uint256 a) internal pure returns (uint256) {
                                            if (a == 0) {
                                                return 0;
                                            }
                                            // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
                                            //
                                            // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
                                            // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
                                            //
                                            // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
                                            // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
                                            // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
                                            //
                                            // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
                                            uint256 result = 1 << (log2(a) >> 1);
                                            // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
                                            // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
                                            // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
                                            // into the expected uint128 result.
                                            unchecked {
                                                result = (result + a / result) >> 1;
                                                result = (result + a / result) >> 1;
                                                result = (result + a / result) >> 1;
                                                result = (result + a / result) >> 1;
                                                result = (result + a / result) >> 1;
                                                result = (result + a / result) >> 1;
                                                result = (result + a / result) >> 1;
                                                return min(result, a / result);
                                            }
                                        }
                                        /**
                                         * @notice Calculates sqrt(a), following the selected rounding direction.
                                         */
                                        function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
                                            unchecked {
                                                uint256 result = sqrt(a);
                                                return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
                                            }
                                        }
                                        /**
                                         * @dev Return the log in base 2, rounded down, of a positive value.
                                         * Returns 0 if given 0.
                                         */
                                        function log2(uint256 value) internal pure returns (uint256) {
                                            uint256 result = 0;
                                            unchecked {
                                                if (value >> 128 > 0) {
                                                    value >>= 128;
                                                    result += 128;
                                                }
                                                if (value >> 64 > 0) {
                                                    value >>= 64;
                                                    result += 64;
                                                }
                                                if (value >> 32 > 0) {
                                                    value >>= 32;
                                                    result += 32;
                                                }
                                                if (value >> 16 > 0) {
                                                    value >>= 16;
                                                    result += 16;
                                                }
                                                if (value >> 8 > 0) {
                                                    value >>= 8;
                                                    result += 8;
                                                }
                                                if (value >> 4 > 0) {
                                                    value >>= 4;
                                                    result += 4;
                                                }
                                                if (value >> 2 > 0) {
                                                    value >>= 2;
                                                    result += 2;
                                                }
                                                if (value >> 1 > 0) {
                                                    result += 1;
                                                }
                                            }
                                            return result;
                                        }
                                        /**
                                         * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
                                         * Returns 0 if given 0.
                                         */
                                        function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
                                            unchecked {
                                                uint256 result = log2(value);
                                                return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
                                            }
                                        }
                                        /**
                                         * @dev Return the log in base 10, rounded down, of a positive value.
                                         * Returns 0 if given 0.
                                         */
                                        function log10(uint256 value) internal pure returns (uint256) {
                                            uint256 result = 0;
                                            unchecked {
                                                if (value >= 10 ** 64) {
                                                    value /= 10 ** 64;
                                                    result += 64;
                                                }
                                                if (value >= 10 ** 32) {
                                                    value /= 10 ** 32;
                                                    result += 32;
                                                }
                                                if (value >= 10 ** 16) {
                                                    value /= 10 ** 16;
                                                    result += 16;
                                                }
                                                if (value >= 10 ** 8) {
                                                    value /= 10 ** 8;
                                                    result += 8;
                                                }
                                                if (value >= 10 ** 4) {
                                                    value /= 10 ** 4;
                                                    result += 4;
                                                }
                                                if (value >= 10 ** 2) {
                                                    value /= 10 ** 2;
                                                    result += 2;
                                                }
                                                if (value >= 10 ** 1) {
                                                    result += 1;
                                                }
                                            }
                                            return result;
                                        }
                                        /**
                                         * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
                                         * Returns 0 if given 0.
                                         */
                                        function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
                                            unchecked {
                                                uint256 result = log10(value);
                                                return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
                                            }
                                        }
                                        /**
                                         * @dev Return the log in base 256, rounded down, of a positive value.
                                         * Returns 0 if given 0.
                                         *
                                         * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
                                         */
                                        function log256(uint256 value) internal pure returns (uint256) {
                                            uint256 result = 0;
                                            unchecked {
                                                if (value >> 128 > 0) {
                                                    value >>= 128;
                                                    result += 16;
                                                }
                                                if (value >> 64 > 0) {
                                                    value >>= 64;
                                                    result += 8;
                                                }
                                                if (value >> 32 > 0) {
                                                    value >>= 32;
                                                    result += 4;
                                                }
                                                if (value >> 16 > 0) {
                                                    value >>= 16;
                                                    result += 2;
                                                }
                                                if (value >> 8 > 0) {
                                                    result += 1;
                                                }
                                            }
                                            return result;
                                        }
                                        /**
                                         * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
                                         * Returns 0 if given 0.
                                         */
                                        function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
                                            unchecked {
                                                uint256 result = log256(value);
                                                return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev Standard signed math utilities missing in the Solidity language.
                                     */
                                    library SignedMath {
                                        /**
                                         * @dev Returns the largest of two signed numbers.
                                         */
                                        function max(int256 a, int256 b) internal pure returns (int256) {
                                            return a > b ? a : b;
                                        }
                                        /**
                                         * @dev Returns the smallest of two signed numbers.
                                         */
                                        function min(int256 a, int256 b) internal pure returns (int256) {
                                            return a < b ? a : b;
                                        }
                                        /**
                                         * @dev Returns the average of two signed numbers without overflow.
                                         * The result is rounded towards zero.
                                         */
                                        function average(int256 a, int256 b) internal pure returns (int256) {
                                            // Formula from the book "Hacker's Delight"
                                            int256 x = (a & b) + ((a ^ b) >> 1);
                                            return x + (int256(uint256(x) >> 255) & (a ^ b));
                                        }
                                        /**
                                         * @dev Returns the absolute unsigned value of a signed value.
                                         */
                                        function abs(int256 n) internal pure returns (uint256) {
                                            unchecked {
                                                // must be unchecked in order to support `n = type(int256).min`
                                                return uint256(n >= 0 ? n : -n);
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity ^0.8.19;
                                    import "@openzeppelin/contracts/access/Ownable.sol";
                                    import "@layerzerolabs/lz-evm-protocol-v2/contracts/libs/Errors.sol";
                                    import "./interfaces/ILayerZeroExecutor.sol";
                                    import "./interfaces/ILayerZeroTreasury.sol";
                                    struct WorkerOptions {
                                        uint8 workerId;
                                        bytes options;
                                    }
                                    enum DeliveryState {
                                        Signing,
                                        Deliverable,
                                        Delivered,
                                        Waiting
                                    }
                                    abstract contract MessageLibBase is Ownable {
                                        address internal immutable endpoint;
                                        uint32 internal immutable localEid;
                                        uint internal immutable treasuryGasCap;
                                        // config
                                        address public treasury;
                                        // accumulated fees for workers and treasury
                                        mapping(address worker => uint) public fees;
                                        event ExecutorFeePaid(address executor, uint fee);
                                        event TreasurySet(address treasury);
                                        // only the endpoint can call SEND() and setConfig()
                                        modifier onlyEndpoint() {
                                            require(endpoint == msg.sender, Errors.PERMISSION_DENIED);
                                            _;
                                        }
                                        constructor(address _endpoint, uint32 _localEid, uint _treasuryGasCap) {
                                            endpoint = _endpoint;
                                            localEid = _localEid;
                                            treasuryGasCap = _treasuryGasCap;
                                        }
                                        // ======================= Internal =======================
                                        function _assertMessageSize(uint _actual, uint _max) internal pure {
                                            require(_actual <= _max, Errors.INVALID_SIZE);
                                        }
                                        function _sendToExecutor(
                                            address _executor,
                                            uint32 _dstEid,
                                            address _sender,
                                            uint _msgSize,
                                            bytes memory _executorOptions
                                        ) internal returns (uint executorFee) {
                                            executorFee = ILayerZeroExecutor(_executor).assignJob(_dstEid, _sender, _msgSize, _executorOptions);
                                            if (executorFee > 0) {
                                                fees[_executor] += executorFee;
                                            }
                                            emit ExecutorFeePaid(_executor, executorFee);
                                        }
                                        function _sendToTreasury(
                                            address _sender,
                                            uint32 _dstEid,
                                            uint _totalNativeFee,
                                            bool _payInLzToken
                                        ) internal returns (uint treasuryNativeFee, uint lzTokenFee) {
                                            // fee should be in lzTokenFee if payInLzToken, otherwise in native
                                            (treasuryNativeFee, lzTokenFee) = _quoteTreasuryFee(_sender, _dstEid, _totalNativeFee, _payInLzToken);
                                            // if payInLzToken, handle in messagelib / endpoint
                                            if (treasuryNativeFee > 0) {
                                                fees[treasury] += treasuryNativeFee;
                                            }
                                        }
                                        function _quote(
                                            address _sender,
                                            uint32 _dstEid,
                                            uint _msgSize,
                                            bool _payInLzToken,
                                            bytes calldata _options
                                        ) internal view returns (uint, uint) {
                                            require(_options.length > 0, Errors.INVALID_ARGUMENT);
                                            (bytes memory executorOptions, WorkerOptions[] memory otherWorkerOptions) = _getExecutorAndOtherOptions(
                                                _options
                                            );
                                            // quote other workers
                                            (uint nativeFee, address executor, uint maxMsgSize) = _quoteWorkers(_sender, _dstEid, otherWorkerOptions);
                                            // assert msg size
                                            _assertMessageSize(_msgSize, maxMsgSize);
                                            // quote executor
                                            nativeFee += ILayerZeroExecutor(executor).getFee(_dstEid, _sender, _msgSize, executorOptions);
                                            // quote treasury
                                            (uint treasuryNativeFee, uint lzTokenFee) = _quoteTreasuryFee(_sender, _dstEid, nativeFee, _payInLzToken);
                                            if (treasuryNativeFee > 0) {
                                                nativeFee += treasuryNativeFee;
                                            }
                                            return (nativeFee, lzTokenFee);
                                        }
                                        function _quoteTreasuryFee(
                                            address _sender,
                                            uint32 _eid,
                                            uint _totalFee,
                                            bool _payInLzToken
                                        ) internal view returns (uint nativeFee, uint lzTokenFee) {
                                            if (treasury != address(0x0)) {
                                                try ILayerZeroTreasury(treasury).getFee(_sender, _eid, _totalFee, _payInLzToken) returns (
                                                    uint treasuryFee
                                                ) {
                                                    // success
                                                    if (_payInLzToken) {
                                                        lzTokenFee = treasuryFee;
                                                    } else {
                                                        // pay in native, make sure that the treasury fee is not higher than the cap
                                                        uint gasFeeEstimate = tx.gasprice * treasuryGasCap;
                                                        // cap is the max of total fee and gasFeeEstimate. this is to prevent apps from forcing the cap to 0.
                                                        uint nativeFeeCap = _totalFee > gasFeeEstimate ? _totalFee : gasFeeEstimate;
                                                        // to prevent the treasury from returning an overly high value to break the path
                                                        nativeFee = treasuryFee > nativeFeeCap ? nativeFeeCap : treasuryFee;
                                                    }
                                                } catch {
                                                    // failure, something wrong with treasury contract, charge nothing and continue
                                                }
                                            }
                                        }
                                        function _transferNative(address _to, uint _amount) internal {
                                            (bool success, ) = _to.call{value: _amount}("");
                                            require(success, Errors.INVALID_STATE);
                                        }
                                        // for msg.sender only
                                        function _assertAndDebitAmount(address _to, uint _amount) internal {
                                            uint fee = fees[msg.sender];
                                            require(_to != address(0x0) && _amount <= fee, Errors.INVALID_ARGUMENT);
                                            unchecked {
                                                fees[msg.sender] = fee - _amount;
                                            }
                                        }
                                        function _setTreasury(address _treasury) internal {
                                            treasury = _treasury;
                                            emit TreasurySet(_treasury);
                                        }
                                        // ======================= Virtual =======================
                                        // For implementation to override
                                        function _quoteWorkers(
                                            address _oapp,
                                            uint32 _eid,
                                            WorkerOptions[] memory _options
                                        ) internal view virtual returns (uint nativeFee, address executor, uint maxMsgSize);
                                        function _getExecutorAndOtherOptions(
                                            bytes calldata _options
                                        ) internal view virtual returns (bytes memory executorOptions, WorkerOptions[] memory otherWorkerOptions);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity ^0.8.19;
                                    import "@openzeppelin/contracts/security/Pausable.sol";
                                    import "@openzeppelin/contracts/access/AccessControl.sol";
                                    import "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/IMessageLib.sol";
                                    import "./interfaces/IWorker.sol";
                                    abstract contract Worker is AccessControl, Pausable, IWorker {
                                        bytes32 internal constant MESSAGE_LIB_ROLE = keccak256("MESSAGE_LIB_ROLE");
                                        bytes32 internal constant ALLOWLIST = keccak256("ALLOWLIST");
                                        bytes32 internal constant DENYLIST = keccak256("DENYLIST");
                                        bytes32 internal constant ADMIN_ROLE = keccak256("ADMIN_ROLE");
                                        address public workerFeeLib;
                                        uint64 public allowlistSize;
                                        uint16 public defaultMultiplierBps;
                                        address public priceFeed;
                                        // ========================= Constructor =========================
                                        /// @param _messageLibs array of message lib addresses that are granted the MESSAGE_LIB_ROLE
                                        /// @param _priceFeed price feed address
                                        /// @param _defaultMultiplierBps default multiplier for worker fee
                                        /// @param _roleAdmin address that is granted the DEFAULT_ADMIN_ROLE (can grant and revoke all roles)
                                        /// @param _admins array of admin addresses that are granted the ADMIN_ROLE
                                        constructor(
                                            address[] memory _messageLibs,
                                            address _priceFeed,
                                            uint16 _defaultMultiplierBps,
                                            address _roleAdmin,
                                            address[] memory _admins
                                        ) {
                                            defaultMultiplierBps = _defaultMultiplierBps;
                                            priceFeed = _priceFeed;
                                            if (_roleAdmin != address(0x0)) {
                                                _grantRole(DEFAULT_ADMIN_ROLE, _roleAdmin); // _roleAdmin can grant and revoke all roles
                                            }
                                            for (uint i = 0; i < _messageLibs.length; ++i) {
                                                _grantRole(MESSAGE_LIB_ROLE, _messageLibs[i]);
                                            }
                                            for (uint i = 0; i < _admins.length; ++i) {
                                                _grantRole(ADMIN_ROLE, _admins[i]);
                                            }
                                        }
                                        // ========================= Modifier =========================
                                        modifier onlyAcl(address _sender) {
                                            require(hasAcl(_sender), "Worker: not allowed");
                                            _;
                                        }
                                        /// @dev Access control list using allowlist and denylist
                                        /// @dev 1) if one address is in the denylist -> deny
                                        /// @dev 2) else if address in the allowlist OR allowlist is empty (allows everyone)-> allow
                                        /// @dev 3) else deny
                                        /// @param _sender address to check
                                        function hasAcl(address _sender) public view returns (bool) {
                                            if (hasRole(DENYLIST, _sender)) {
                                                return false;
                                            } else if (allowlistSize == 0 || hasRole(ALLOWLIST, _sender)) {
                                                return true;
                                            } else {
                                                return false;
                                            }
                                        }
                                        // ========================= OnyDefaultAdmin =========================
                                        /// @dev flag to pause execution of workers (if used with whenNotPaused modifier)
                                        /// @param _paused true to pause, false to unpause
                                        function setPaused(bool _paused) external onlyRole(DEFAULT_ADMIN_ROLE) {
                                            if (_paused) {
                                                _pause();
                                            } else {
                                                _unpause();
                                            }
                                        }
                                        // ========================= OnlyAdmin =========================
                                        /// @param _priceFeed price feed address
                                        function setPriceFeed(address _priceFeed) external onlyRole(ADMIN_ROLE) {
                                            priceFeed = _priceFeed;
                                            emit SetPriceFeed(_priceFeed);
                                        }
                                        /// @param _workerFeeLib worker fee lib address
                                        function setWorkerFeeLib(address _workerFeeLib) external onlyRole(ADMIN_ROLE) {
                                            workerFeeLib = _workerFeeLib;
                                            emit SetWorkerLib(_workerFeeLib);
                                        }
                                        /// @param _multiplierBps default multiplier for worker fee
                                        function setDefaultMultiplierBps(uint16 _multiplierBps) external onlyRole(ADMIN_ROLE) {
                                            defaultMultiplierBps = _multiplierBps;
                                            emit SetDefaultMultiplierBps(_multiplierBps);
                                        }
                                        /// @dev supports withdrawing fee from ULN301, ULN302 and more
                                        /// @param _lib message lib address
                                        /// @param _to address to withdraw fee to
                                        /// @param _amount amount to withdraw
                                        function withdrawFee(address _lib, address _to, uint _amount) external onlyRole(ADMIN_ROLE) {
                                            require(hasRole(MESSAGE_LIB_ROLE, _lib), "Worker: Invalid message lib");
                                            IMessageLib(_lib).withdrawFee(_to, _amount);
                                            emit Withdraw(_lib, _to, _amount);
                                        }
                                        // ========================= Internal Functions =========================
                                        /// @dev overrides AccessControl to allow for counting of allowlistSize
                                        /// @param _role role to grant
                                        /// @param _account address to grant role to
                                        function _grantRole(bytes32 _role, address _account) internal override {
                                            if (_role == ALLOWLIST && !hasRole(_role, _account)) {
                                                ++allowlistSize;
                                            }
                                            super._grantRole(_role, _account);
                                        }
                                        /// @dev overrides AccessControl to allow for counting of allowlistSize
                                        /// @param _role role to revoke
                                        /// @param _account address to revoke role from
                                        function _revokeRole(bytes32 _role, address _account) internal override {
                                            if (_role == ALLOWLIST && hasRole(_role, _account)) {
                                                --allowlistSize;
                                            }
                                            super._revokeRole(_role, _account);
                                        }
                                        /// @dev overrides AccessControl to disable renouncing of roles
                                        function renounceRole(bytes32 /*role*/, address /*account*/) public pure override {
                                            revert("Worker: cannot renounce role");
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface ILayerZeroExecutor {
                                        // @notice query price and assign jobs at the same time
                                        // @param _dstEid - the destination endpoint identifier
                                        // @param _sender - the source sending contract address. executors may apply price discrimination to senders
                                        // @param _calldataSize - dynamic data size of message + caller params
                                        // @param _options - optional parameters for extra service plugins, e.g. sending dust tokens at the destination chain
                                        function assignJob(
                                            uint32 _dstEid,
                                            address _sender,
                                            uint _calldataSize,
                                            bytes calldata _options
                                        ) external payable returns (uint price);
                                        // @notice query the executor price for relaying the payload and its proof to the destination chain
                                        // @param _dstEid - the destination endpoint identifier
                                        // @param _sender - the source sending contract address. executors may apply price discrimination to senders
                                        // @param _calldataSize - dynamic data size of message + caller params
                                        // @param _options - optional parameters for extra service plugins, e.g. sending dust tokens at the destination chain
                                        function getFee(
                                            uint32 _dstEid,
                                            address _sender,
                                            uint _calldataSize,
                                            bytes calldata _options
                                        ) external view returns (uint price);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface ILayerZeroTreasury {
                                        function getFee(address _sender, uint32 _eid, uint _totalFee, bool _payInLzToken) external view returns (uint);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface IWorker {
                                        event SetWorkerLib(address workerLib);
                                        event SetPriceFeed(address priceFeed);
                                        event SetDefaultMultiplierBps(uint16 multiplierBps);
                                        event Withdraw(address lib, address to, uint amount);
                                        function setPriceFeed(address _priceFeed) external;
                                        function priceFeed() external view returns (address);
                                        function setDefaultMultiplierBps(uint16 _multiplierBps) external;
                                        function defaultMultiplierBps() external view returns (uint16);
                                        function withdrawFee(address _lib, address _to, uint _amount) external;
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity ^0.8.19;
                                    import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
                                    abstract contract MultiSig {
                                        enum Errors {
                                            NoError,
                                            SignatureError,
                                            DuplicatedSigner,
                                            SignerNotInCommittee
                                        }
                                        mapping(address signer => bool active) public signers;
                                        uint64 public signerSize;
                                        uint64 public quorum;
                                        event UpdateSigner(address _signer, bool _active);
                                        event UpdateQuorum(uint64 _quorum);
                                        modifier onlySigner() {
                                            require(signers[msg.sender], "MultiSig: caller must be signer");
                                            _;
                                        }
                                        constructor(address[] memory _signers, uint64 _quorum) {
                                            require(_signers.length >= _quorum && _quorum > 0, "MultiSig: signers too few");
                                            address lastSigner = address(0);
                                            for (uint i = 0; i < _signers.length; i++) {
                                                address signer = _signers[i];
                                                require(signer > lastSigner, "MultiSig: signers not sorted"); // to ensure no duplicates
                                                signers[signer] = true;
                                                lastSigner = signer;
                                            }
                                            signerSize = uint64(_signers.length);
                                            quorum = _quorum;
                                        }
                                        function _setSigner(address _signer, bool _active) internal {
                                            require(signers[_signer] != _active, "MultiSig: signer already in that state");
                                            signers[_signer] = _active;
                                            signerSize = _active ? signerSize + 1 : signerSize - 1;
                                            require(signerSize >= quorum, "MultiSig: committee size < threshold");
                                            emit UpdateSigner(_signer, _active);
                                        }
                                        function _setQuorum(uint64 _quorum) internal {
                                            require(_quorum <= signerSize && _quorum > 0, "MultiSig: invalid quorum");
                                            quorum = _quorum;
                                            emit UpdateQuorum(_quorum);
                                        }
                                        function verifySignatures(bytes32 _hash, bytes calldata _signatures) public view returns (bool, Errors) {
                                            if (_signatures.length != uint(quorum) * 65) {
                                                return (false, Errors.SignatureError);
                                            }
                                            bytes32 messageDigest = _getEthSignedMessageHash(_hash);
                                            address lastSigner = address(0); // There cannot be a signer with address 0.
                                            for (uint i = 0; i < quorum; i++) {
                                                bytes calldata signature = _signatures[i * 65:(i + 1) * 65];
                                                (address currentSigner, ECDSA.RecoverError error) = ECDSA.tryRecover(messageDigest, signature);
                                                if (error != ECDSA.RecoverError.NoError) return (false, Errors.SignatureError);
                                                if (currentSigner <= lastSigner) return (false, Errors.DuplicatedSigner); // prevent duplicate signatures
                                                if (!signers[currentSigner]) return (false, Errors.SignerNotInCommittee); // signature is not in committee
                                                lastSigner = currentSigner;
                                            }
                                            return (true, Errors.NoError);
                                        }
                                        function _getEthSignedMessageHash(bytes32 _messageHash) internal pure returns (bytes32) {
                                            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
                                    32", _messageHash));
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity ^0.8.19;
                                    import "@layerzerolabs/lz-evm-v1-0.8/contracts/interfaces/ILayerZeroUltraLightNodeV2.sol";
                                    import "../Worker.sol";
                                    import "./MultiSig.sol";
                                    import "./interfaces/IVerifier.sol";
                                    import "./interfaces/IVerifierFeeLib.sol";
                                    import "./interfaces/IUltraLightNode.sol";
                                    import {DeliveryState} from "../MessageLibBase.sol";
                                    struct ExecuteParam {
                                        uint32 vid;
                                        address target;
                                        bytes callData;
                                        uint expiration;
                                        bytes signatures;
                                    }
                                    contract VerifierNetwork is Worker, MultiSig, IVerifier {
                                        // to uniquely identify this VerifierNetwork instance
                                        // set to endpoint v1 eid if available OR endpoint v2 eid % 30_000
                                        uint32 public immutable vid;
                                        mapping(uint32 dstEid => DstConfig) public dstConfig;
                                        mapping(bytes32 executableHash => bool used) public usedHashes;
                                        event VerifySignaturesFailed(uint idx);
                                        event ExecuteFailed(uint _index, bytes _data);
                                        event HashAlreadyUsed(ExecuteParam param, bytes32 _hash);
                                        event VerifierFeePaid(uint fee);
                                        // ========================= Constructor =========================
                                        /// @dev VerifierNetwork doesn't have a roleAdmin (address(0x0))
                                        /// @dev Supports all of ULNv2, ULN301, ULN302 and more
                                        /// @param _messageLibs array of message lib addresses that are granted the MESSAGE_LIB_ROLE
                                        /// @param _priceFeed price feed address
                                        /// @param _signers array of signer addresses for multisig
                                        /// @param _quorum quorum for multisig
                                        /// @param _admins array of admin addresses that are granted the ADMIN_ROLE
                                        constructor(
                                            uint32 _vid,
                                            address[] memory _messageLibs,
                                            address _priceFeed,
                                            address[] memory _signers,
                                            uint64 _quorum,
                                            address[] memory _admins
                                        ) Worker(_messageLibs, _priceFeed, 12000, address(0x0), _admins) MultiSig(_signers, _quorum) {
                                            vid = _vid;
                                        }
                                        // ========================= Modifier =========================
                                        /// @dev depending on role, restrict access to only self or admin
                                        /// @dev ALLOWLIST, DENYLIST, MESSAGE_LIB_ROLE can only be granted/revoked by self
                                        /// @dev ADMIN_ROLE can only be granted/revoked by admin
                                        /// @dev reverts if not one of the above roles
                                        /// @param _role role to check
                                        modifier onlySelfOrAdmin(bytes32 _role) {
                                            if (_role == ALLOWLIST || _role == DENYLIST || _role == MESSAGE_LIB_ROLE) {
                                                // self required
                                                require(address(this) == msg.sender, "Verifier: caller must be self");
                                            } else if (_role == ADMIN_ROLE) {
                                                // admin required
                                                _checkRole(ADMIN_ROLE);
                                            } else {
                                                revert("Verifier: invalid role");
                                            }
                                            _;
                                        }
                                        modifier onlySelf() {
                                            require(address(this) == msg.sender, "Verifier: caller must be self");
                                            _;
                                        }
                                        // ========================= OnlySelf =========================
                                        /// @dev set signers for multisig
                                        /// @dev function sig 0x31cb6105
                                        /// @param _signer signer address
                                        /// @param _active true to add, false to remove
                                        function setSigner(address _signer, bool _active) external onlySelf {
                                            _setSigner(_signer, _active);
                                        }
                                        /// @dev set quorum for multisig
                                        /// @dev function sig 0x8585c945
                                        /// @param _quorum to set
                                        function setQuorum(uint64 _quorum) external onlySelf {
                                            _setQuorum(_quorum);
                                        }
                                        /// @dev one function to verify and deliver to ULN302 and more (does not support ULN301)
                                        /// @dev if last verifier, can use this function to save overhead gas on deliver
                                        /// @dev function sig 0xb724b133
                                        /// @param _uln IUltraLightNode compatible contract
                                        /// @param _packetHeader packet header
                                        /// @param _payloadHash payload hash
                                        /// @param _confirmations block confirmations
                                        function verifyAndDeliver(
                                            IUltraLightNode _uln,
                                            bytes calldata _packetHeader,
                                            bytes32 _payloadHash,
                                            uint64 _confirmations
                                        ) external onlySelf {
                                            require(hasRole(MESSAGE_LIB_ROLE, address(_uln)), "Verifier: invalid uln");
                                            _uln.verify(_packetHeader, _payloadHash, _confirmations);
                                            // if deliverable, deliver. else, skip or it will revert in uln
                                            if (_uln.deliverable(_packetHeader, _payloadHash) == DeliveryState.Deliverable) {
                                                _uln.deliver(_packetHeader, _payloadHash);
                                            }
                                        }
                                        // ========================= OnlySelf / OnlyAdmin =========================
                                        /// @dev overrides AccessControl to allow self/admin to grant role'
                                        /// @dev function sig 0x2f2ff15d
                                        /// @param _role role to grant
                                        /// @param _account account to grant role to
                                        function grantRole(bytes32 _role, address _account) public override onlySelfOrAdmin(_role) {
                                            _grantRole(_role, _account);
                                        }
                                        /// @dev overrides AccessControl to allow self/admin to revoke role
                                        /// @dev function sig 0xd547741f
                                        /// @param _role role to revoke
                                        /// @param _account account to revoke role from
                                        function revokeRole(bytes32 _role, address _account) public override onlySelfOrAdmin(_role) {
                                            _revokeRole(_role, _account);
                                        }
                                        // ========================= OnlyQuorum =========================
                                        // @notice function for quorum to change admin without going through execute function
                                        // @dev calldata in the case is abi.encode new admin address
                                        function quorumChangeAdmin(ExecuteParam calldata _param) external {
                                            require(_param.expiration > block.timestamp, "Verifier: expired");
                                            require(_param.target == address(this), "Verifier: invalid target");
                                            require(_param.vid == vid, "Verifier: invalid vid");
                                            // generate and validate hash
                                            bytes32 hash = hashCallData(_param.vid, _param.target, _param.callData, _param.expiration);
                                            (bool sigsValid, ) = verifySignatures(hash, _param.signatures);
                                            require(sigsValid, "Verifier: invalid signatures");
                                            require(!usedHashes[hash], "Verifier: hash already used");
                                            usedHashes[hash] = true;
                                            _grantRole(ADMIN_ROLE, abi.decode(_param.callData, (address)));
                                        }
                                        // ========================= OnlyAdmin =========================
                                        /// @param _params array of DstConfigParam
                                        function setDstConfig(DstConfigParam[] calldata _params) external onlyRole(ADMIN_ROLE) {
                                            for (uint i = 0; i < _params.length; ++i) {
                                                DstConfigParam calldata param = _params[i];
                                                dstConfig[param.dstEid] = DstConfig(param.gas, param.multiplierBps, param.floorMarginUSD);
                                            }
                                            emit SetDstConfig(_params);
                                        }
                                        /// @dev takes a list of instructions and executes them in order
                                        /// @dev if any of the instructions fail, it will emit an error event and continue to execute the rest of the instructions
                                        /// @param _params array of ExecuteParam, includes target, callData, expiration, signatures
                                        function execute(ExecuteParam[] calldata _params) external onlyRole(ADMIN_ROLE) {
                                            for (uint i = 0; i < _params.length; ++i) {
                                                ExecuteParam calldata param = _params[i];
                                                // 1. skip if invalid vid
                                                if (param.vid != vid) {
                                                    continue;
                                                }
                                                // 2. skip if expired
                                                if (param.expiration <= block.timestamp) {
                                                    continue;
                                                }
                                                // generate and validate hash
                                                bytes32 hash = hashCallData(param.vid, param.target, param.callData, param.expiration);
                                                // 3. check signatures
                                                (bool sigsValid, ) = verifySignatures(hash, param.signatures);
                                                if (!sigsValid) {
                                                    emit VerifySignaturesFailed(i);
                                                    continue;
                                                }
                                                // 4. should check hash
                                                bool shouldCheckHash = _shouldCheckHash(bytes4(param.callData));
                                                if (shouldCheckHash) {
                                                    if (usedHashes[hash]) {
                                                        emit HashAlreadyUsed(param, hash);
                                                        continue;
                                                    } else {
                                                        usedHashes[hash] = true; // prevent reentry and replay attack
                                                    }
                                                }
                                                (bool success, bytes memory rtnData) = param.target.call(param.callData);
                                                if (!success) {
                                                    if (shouldCheckHash) {
                                                        // need to unset the usedHash otherwise it cant be used
                                                        usedHashes[hash] = false;
                                                    }
                                                    // emit an event in any case
                                                    emit ExecuteFailed(i, rtnData);
                                                }
                                            }
                                        }
                                        /// @dev to support ULNv2
                                        /// @dev the withdrawFee function for ULN30X is built in the Worker contract
                                        /// @param _lib message lib address
                                        /// @param _to address to withdraw to
                                        /// @param _amount amount to withdraw
                                        function withdrawFeeFromUlnV2(address _lib, address payable _to, uint _amount) external onlyRole(ADMIN_ROLE) {
                                            require(hasRole(MESSAGE_LIB_ROLE, _lib), "Verifier: Invalid message lib");
                                            ILayerZeroUltraLightNodeV2(_lib).withdrawNative(_to, _amount);
                                        }
                                        // ========================= OnlyMessageLib =========================
                                        /// @dev for ULN301, ULN302 and more to assign job
                                        /// @dev verifier network can reject job from _sender by adding/removing them from allowlist/denylist
                                        /// @param _param assign job param
                                        /// @param _options verifier options
                                        function assignJob(
                                            AssignJobParam calldata _param,
                                            bytes calldata _options
                                        ) external payable onlyRole(MESSAGE_LIB_ROLE) onlyAcl(_param.sender) returns (uint totalFee) {
                                            IVerifierFeeLib.FeeParams memory feeParams = IVerifierFeeLib.FeeParams(
                                                priceFeed,
                                                _param.dstEid,
                                                _param.confirmations,
                                                _param.sender,
                                                quorum,
                                                defaultMultiplierBps
                                            );
                                            totalFee = IVerifierFeeLib(workerFeeLib).getFeeOnSend(feeParams, dstConfig[_param.dstEid], _options);
                                        }
                                        /// @dev to support ULNv2
                                        /// @dev verifier network can reject job from _sender by adding/removing them from allowlist/denylist
                                        /// @param _dstEid destination EndpointId
                                        /// @param //_outboundProofType outbound proof type
                                        /// @param _confirmations block confirmations
                                        /// @param _sender message sender address
                                        function assignJob(
                                            uint16 _dstEid,
                                            uint16 /*_outboundProofType*/,
                                            uint64 _confirmations,
                                            address _sender
                                        ) external onlyRole(MESSAGE_LIB_ROLE) onlyAcl(_sender) returns (uint totalFee) {
                                            IVerifierFeeLib.FeeParams memory params = IVerifierFeeLib.FeeParams(
                                                priceFeed,
                                                _dstEid,
                                                _confirmations,
                                                _sender,
                                                quorum,
                                                defaultMultiplierBps
                                            );
                                            // ULNV2 does not have verifier options
                                            totalFee = IVerifierFeeLib(workerFeeLib).getFeeOnSend(params, dstConfig[_dstEid], bytes(""));
                                            emit VerifierFeePaid(totalFee);
                                        }
                                        // ========================= View =========================
                                        /// @dev getFee can revert if _sender doesn't pass ACL
                                        /// @param _dstEid destination EndpointId
                                        /// @param _confirmations block confirmations
                                        /// @param _sender message sender address
                                        /// @param _options verifier options
                                        /// @return fee fee in native amount
                                        function getFee(
                                            uint32 _dstEid,
                                            uint64 _confirmations,
                                            address _sender,
                                            bytes calldata _options
                                        ) external view onlyAcl(_sender) returns (uint fee) {
                                            IVerifierFeeLib.FeeParams memory params = IVerifierFeeLib.FeeParams(
                                                priceFeed,
                                                _dstEid,
                                                _confirmations,
                                                _sender,
                                                quorum,
                                                defaultMultiplierBps
                                            );
                                            return IVerifierFeeLib(workerFeeLib).getFee(params, dstConfig[_dstEid], _options);
                                        }
                                        /// @dev to support ULNv2
                                        /// @dev getFee can revert if _sender doesn't pass ACL
                                        /// @param _dstEid destination EndpointId
                                        /// @param //_outboundProofType outbound proof type
                                        /// @param _confirmations block confirmations
                                        /// @param _sender message sender address
                                        function getFee(
                                            uint16 _dstEid,
                                            uint16 /*_outboundProofType*/,
                                            uint64 _confirmations,
                                            address _sender
                                        ) public view onlyAcl(_sender) returns (uint fee) {
                                            IVerifierFeeLib.FeeParams memory params = IVerifierFeeLib.FeeParams(
                                                priceFeed,
                                                _dstEid,
                                                _confirmations,
                                                _sender,
                                                quorum,
                                                defaultMultiplierBps
                                            );
                                            return IVerifierFeeLib(workerFeeLib).getFee(params, dstConfig[_dstEid], bytes(""));
                                        }
                                        /// @param _target target address
                                        /// @param _callData call data
                                        /// @param _expiration expiration timestamp
                                        /// @return hash of above
                                        function hashCallData(
                                            uint32 _vid,
                                            address _target,
                                            bytes calldata _callData,
                                            uint _expiration
                                        ) public pure returns (bytes32) {
                                            return keccak256(abi.encodePacked(_vid, _target, _expiration, _callData));
                                        }
                                        // ========================= Internal =========================
                                        /// @dev to save gas, we don't check hash for some functions (where replaying won't change the state)
                                        /// @dev for example, some administrative functions like changing signers, the contract should check hash to double spending
                                        /// @dev should ensure that all onlySelf functions have unique functionSig
                                        /// @param _functionSig function signature
                                        /// @return true if should check hash
                                        function _shouldCheckHash(bytes4 _functionSig) internal pure returns (bool) {
                                            // never check for these selectors to save gas
                                            return
                                                _functionSig != IUltraLightNode.verify.selector && // 0x0223536e, replaying won't change the state
                                                _functionSig != this.verifyAndDeliver.selector && // 0xb724b133, replaying calls deliver on top of verify, which will be rejected at uln if not deliverable
                                                _functionSig != ILayerZeroUltraLightNodeV2.updateHash.selector; // 0x704316e5, replaying will be revert at uln
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface ILayerZeroVerifier {
                                        struct AssignJobParam {
                                            uint32 dstEid;
                                            bytes packetHeader;
                                            bytes32 payloadHash;
                                            uint64 confirmations;
                                            address sender;
                                        }
                                        // @notice query price and assign jobs at the same time
                                        // @param _dstEid - the destination endpoint identifier
                                        // @param _packetHeader - version + nonce + path
                                        // @param _payloadHash - hash of guid + message
                                        // @param _confirmations - block confirmation delay before relaying blocks
                                        // @param _sender - the source sending contract address
                                        // @param _options - options
                                        function assignJob(AssignJobParam calldata _param, bytes calldata _options) external payable returns (uint fee);
                                        // @notice query the verifier fee for relaying block information to the destination chain
                                        // @param _dstEid the destination endpoint identifier
                                        // @param _confirmations - block confirmation delay before relaying blocks
                                        // @param _sender - the source sending contract address
                                        // @param _options - options
                                        function getFee(
                                            uint32 _dstEid,
                                            uint64 _confirmations,
                                            address _sender,
                                            bytes calldata _options
                                        ) external view returns (uint fee);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    import {DeliveryState} from "../../MessageLibBase.sol";
                                    interface IUltraLightNode {
                                        function verify(bytes calldata _packetHeader, bytes32 _payloadHash, uint64 _confirmations) external;
                                        function deliver(bytes calldata _packetHeader, bytes32 _payloadHash) external;
                                        function deliverable(bytes calldata _packetHeader, bytes32 _payloadHash) external view returns (DeliveryState);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    import "../../interfaces/IWorker.sol";
                                    import "./ILayerZeroVerifier.sol";
                                    interface IVerifier is IWorker, ILayerZeroVerifier {
                                        struct DstConfigParam {
                                            uint32 dstEid;
                                            uint64 gas;
                                            uint16 multiplierBps;
                                            uint128 floorMarginUSD;
                                        }
                                        struct DstConfig {
                                            uint64 gas;
                                            uint16 multiplierBps;
                                            uint128 floorMarginUSD; // uses priceFeed PRICE_RATIO_DENOMINATOR
                                        }
                                        event SetDstConfig(DstConfigParam[] params);
                                        function dstConfig(uint32 _dstEid) external view returns (uint64, uint16, uint128);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    import "./IVerifier.sol";
                                    interface IVerifierFeeLib {
                                        struct FeeParams {
                                            address priceFeed;
                                            uint32 dstEid;
                                            uint64 confirmations;
                                            address sender;
                                            uint64 quorum;
                                            uint16 defaultMultiplierBps;
                                        }
                                        function getFeeOnSend(
                                            FeeParams memory _params,
                                            IVerifier.DstConfig memory _dstConfig,
                                            bytes memory _options
                                        ) external payable returns (uint fee);
                                        function getFee(
                                            FeeParams calldata _params,
                                            IVerifier.DstConfig calldata _dstConfig,
                                            bytes calldata _options
                                        ) external view returns (uint fee);
                                    }
                                    

                                    File 6 of 12: USDCProxyOFTV2
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.8.0;
                                    import "@layerzerolabs/solidity-examples/contracts/token/oft/v2/ProxyOFTV2.sol";
                                    contract USDCProxyOFTV2 is ProxyOFTV2 {
                                        constructor(address _token, address _layerZeroEndpoint) ProxyOFTV2(_token, 6, _layerZeroEndpoint){}
                                    }// 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/extensions/draft-IERC20Permit.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
                                     * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
                                     *
                                     * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
                                     * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
                                     * need to send a transaction, and thus is not required to hold Ether at all.
                                     */
                                    interface IERC20Permit {
                                        /**
                                         * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
                                         * given ``owner``'s signed approval.
                                         *
                                         * IMPORTANT: The same issues {IERC20-approve} has related to transaction
                                         * ordering also apply here.
                                         *
                                         * Emits an {Approval} event.
                                         *
                                         * Requirements:
                                         *
                                         * - `spender` cannot be the zero address.
                                         * - `deadline` must be a timestamp in the future.
                                         * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
                                         * over the EIP712-formatted function arguments.
                                         * - the signature must use ``owner``'s current nonce (see {nonces}).
                                         *
                                         * For more information on the signature format, see the
                                         * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
                                         * section].
                                         */
                                        function permit(
                                            address owner,
                                            address spender,
                                            uint256 value,
                                            uint256 deadline,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) external;
                                        /**
                                         * @dev Returns the current nonce for `owner`. This value must be
                                         * included whenever a signature is generated for {permit}.
                                         *
                                         * Every successful call to {permit} increases ``owner``'s nonce by one. This
                                         * prevents a signature from being used multiple times.
                                         */
                                        function nonces(address owner) external view returns (uint256);
                                        /**
                                         * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
                                         */
                                        // solhint-disable-next-line func-name-mixedcase
                                        function DOMAIN_SEPARATOR() external view returns (bytes32);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.8.0) (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 functionCallWithValue(target, data, 0, "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");
                                            (bool success, bytes memory returndata) = target.call{value: value}(data);
                                            return verifyCallResultFromTarget(target, 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) {
                                            (bool success, bytes memory returndata) = target.staticcall(data);
                                            return verifyCallResultFromTarget(target, 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) {
                                            (bool success, bytes memory returndata) = target.delegatecall(data);
                                            return verifyCallResultFromTarget(target, success, returndata, errorMessage);
                                        }
                                        /**
                                         * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
                                         * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
                                         *
                                         * _Available since v4.8._
                                         */
                                        function verifyCallResultFromTarget(
                                            address target,
                                            bool success,
                                            bytes memory returndata,
                                            string memory errorMessage
                                        ) internal view returns (bytes memory) {
                                            if (success) {
                                                if (returndata.length == 0) {
                                                    // only check isContract if the call was successful and the return data is empty
                                                    // otherwise we already know that it was a contract
                                                    require(isContract(target), "Address: call to non-contract");
                                                }
                                                return returndata;
                                            } else {
                                                _revert(returndata, errorMessage);
                                            }
                                        }
                                        /**
                                         * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
                                         * revert reason or 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 {
                                                _revert(returndata, errorMessage);
                                            }
                                        }
                                        function _revert(bytes memory returndata, string memory errorMessage) private pure {
                                            // Look for revert reason and bubble it up if present
                                            if (returndata.length > 0) {
                                                // The easiest way to bubble the revert reason is using memory via assembly
                                                /// @solidity memory-safe-assembly
                                                assembly {
                                                    let returndata_size := mload(returndata)
                                                    revert(add(32, returndata), returndata_size)
                                                }
                                            } else {
                                                revert(errorMessage);
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev Interface of the ERC165 standard, as defined in the
                                     * https://eips.ethereum.org/EIPS/eip-165[EIP].
                                     *
                                     * Implementers can declare support of contract interfaces, which can then be
                                     * queried by others ({ERC165Checker}).
                                     *
                                     * For an implementation, see {ERC165}.
                                     */
                                    interface IERC165 {
                                        /**
                                         * @dev Returns true if this contract implements the interface defined by
                                         * `interfaceId`. See the corresponding
                                         * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                                         * to learn more about how these ids are created.
                                         *
                                         * This function call must use less than 30 000 gas.
                                         */
                                        function supportsInterface(bytes4 interfaceId) external view returns (bool);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity >=0.5.0;
                                    import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
                                    /**
                                     * @dev Interface of the IOFT core standard
                                     */
                                    interface ICommonOFT is IERC165 {
                                        struct LzCallParams {
                                            address payable refundAddress;
                                            address zroPaymentAddress;
                                            bytes adapterParams;
                                        }
                                        /**
                                         * @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
                                         * _dstChainId - L0 defined chain id to send tokens too
                                         * _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
                                         * _amount - amount of the tokens to transfer
                                         * _useZro - indicates to use zro to pay L0 fees
                                         * _adapterParam - flexible bytes array to indicate messaging adapter services in L0
                                         */
                                        function estimateSendFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);
                                        function estimateSendAndCallFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);
                                        /**
                                         * @dev returns the circulating amount of tokens on current chain
                                         */
                                        function circulatingSupply() external view returns (uint);
                                        /**
                                         * @dev returns the address of the ERC20 token
                                         */
                                        function token() external view returns (address);
                                    }
                                    // 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;
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.7.0) (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 Throws if called by any account other than the owner.
                                         */
                                        modifier onlyOwner() {
                                            _checkOwner();
                                            _;
                                        }
                                        /**
                                         * @dev Returns the address of the current owner.
                                         */
                                        function owner() public view virtual returns (address) {
                                            return _owner;
                                        }
                                        /**
                                         * @dev Throws if the sender is not the owner.
                                         */
                                        function _checkOwner() internal view virtual {
                                            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
                                    pragma solidity >=0.5.0;
                                    interface ILayerZeroReceiver {
                                        // @notice LayerZero endpoint will invoke this function to deliver the message on the destination
                                        // @param _srcChainId - the source endpoint identifier
                                        // @param _srcAddress - the source sending contract address from the source chain
                                        // @param _nonce - the ordered message nonce
                                        // @param _payload - the signed payload is the UA bytes has encoded to be sent
                                        function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) external;
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity >=0.5.0;
                                    interface ILayerZeroUserApplicationConfig {
                                        // @notice set the configuration of the LayerZero messaging library of the specified version
                                        // @param _version - messaging library version
                                        // @param _chainId - the chainId for the pending config change
                                        // @param _configType - type of configuration. every messaging library has its own convention.
                                        // @param _config - configuration in the bytes. can encode arbitrary content.
                                        function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external;
                                        // @notice set the send() LayerZero messaging library version to _version
                                        // @param _version - new messaging library version
                                        function setSendVersion(uint16 _version) external;
                                        // @notice set the lzReceive() LayerZero messaging library version to _version
                                        // @param _version - new messaging library version
                                        function setReceiveVersion(uint16 _version) external;
                                        // @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
                                        // @param _srcChainId - the chainId of the source chain
                                        // @param _srcAddress - the contract address of the source contract at the source chain
                                        function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external;
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity >=0.5.0;
                                    import "./ILayerZeroUserApplicationConfig.sol";
                                    interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
                                        // @notice send a LayerZero message to the specified address at a LayerZero endpoint.
                                        // @param _dstChainId - the destination chain identifier
                                        // @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
                                        // @param _payload - a custom bytes payload to send to the destination contract
                                        // @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
                                        // @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
                                        // @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
                                        function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
                                        // @notice used by the messaging library to publish verified payload
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source contract (as bytes) at the source chain
                                        // @param _dstAddress - the address on destination chain
                                        // @param _nonce - the unbound message ordering nonce
                                        // @param _gasLimit - the gas limit for external contract execution
                                        // @param _payload - verified payload to send to the destination contract
                                        function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _payload) external;
                                        // @notice get the inboundNonce of a lzApp from a source chain which could be EVM or non-EVM chain
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source chain contract address
                                        function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (uint64);
                                        // @notice get the outboundNonce from this source chain which, consequently, is always an EVM
                                        // @param _srcAddress - the source chain contract address
                                        function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view returns (uint64);
                                        // @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
                                        // @param _dstChainId - the destination chain identifier
                                        // @param _userApplication - the user app address on this EVM chain
                                        // @param _payload - the custom message to send over LayerZero
                                        // @param _payInZRO - if false, user app pays the protocol fee in native token
                                        // @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
                                        function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);
                                        // @notice get this Endpoint's immutable source identifier
                                        function getChainId() external view returns (uint16);
                                        // @notice the interface to retry failed message on this Endpoint destination
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source chain contract address
                                        // @param _payload - the payload to be retried
                                        function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _payload) external;
                                        // @notice query if any STORED payload (message blocking) at the endpoint.
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source chain contract address
                                        function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool);
                                        // @notice query if the _libraryAddress is valid for sending msgs.
                                        // @param _userApplication - the user app address on this EVM chain
                                        function getSendLibraryAddress(address _userApplication) external view returns (address);
                                        // @notice query if the _libraryAddress is valid for receiving msgs.
                                        // @param _userApplication - the user app address on this EVM chain
                                        function getReceiveLibraryAddress(address _userApplication) external view returns (address);
                                        // @notice query if the non-reentrancy guard for send() is on
                                        // @return true if the guard is on. false otherwise
                                        function isSendingPayload() external view returns (bool);
                                        // @notice query if the non-reentrancy guard for receive() is on
                                        // @return true if the guard is on. false otherwise
                                        function isReceivingPayload() external view returns (bool);
                                        // @notice get the configuration of the LayerZero messaging library of the specified version
                                        // @param _version - messaging library version
                                        // @param _chainId - the chainId for the pending config change
                                        // @param _userApplication - the contract address of the user application
                                        // @param _configType - type of configuration. every messaging library has its own convention.
                                        function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);
                                        // @notice get the send() LayerZero messaging library version
                                        // @param _userApplication - the contract address of the user application
                                        function getSendVersion(address _userApplication) external view returns (uint16);
                                        // @notice get the lzReceive() LayerZero messaging library version
                                        // @param _userApplication - the contract address of the user application
                                        function getReceiveVersion(address _userApplication) external view returns (uint16);
                                    }
                                    // SPDX-License-Identifier: Unlicense
                                    /*
                                     * @title Solidity Bytes Arrays Utils
                                     * @author Gonçalo Sá <[email protected]>
                                     *
                                     * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
                                     *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
                                     */
                                    pragma solidity >=0.8.0 <0.9.0;
                                    library BytesLib {
                                        function concat(
                                            bytes memory _preBytes,
                                            bytes memory _postBytes
                                        )
                                        internal
                                        pure
                                        returns (bytes memory)
                                        {
                                            bytes memory tempBytes;
                                            assembly {
                                            // Get a location of some free memory and store it in tempBytes as
                                            // Solidity does for memory variables.
                                                tempBytes := mload(0x40)
                                            // Store the length of the first bytes array at the beginning of
                                            // the memory for tempBytes.
                                                let length := mload(_preBytes)
                                                mstore(tempBytes, length)
                                            // Maintain a memory counter for the current write location in the
                                            // temp bytes array by adding the 32 bytes for the array length to
                                            // the starting location.
                                                let mc := add(tempBytes, 0x20)
                                            // Stop copying when the memory counter reaches the length of the
                                            // first bytes array.
                                                let end := add(mc, length)
                                                for {
                                                // Initialize a copy counter to the start of the _preBytes data,
                                                // 32 bytes into its memory.
                                                    let cc := add(_preBytes, 0x20)
                                                } lt(mc, end) {
                                                // Increase both counters by 32 bytes each iteration.
                                                    mc := add(mc, 0x20)
                                                    cc := add(cc, 0x20)
                                                } {
                                                // Write the _preBytes data into the tempBytes memory 32 bytes
                                                // at a time.
                                                    mstore(mc, mload(cc))
                                                }
                                            // Add the length of _postBytes to the current length of tempBytes
                                            // and store it as the new length in the first 32 bytes of the
                                            // tempBytes memory.
                                                length := mload(_postBytes)
                                                mstore(tempBytes, add(length, mload(tempBytes)))
                                            // Move the memory counter back from a multiple of 0x20 to the
                                            // actual end of the _preBytes data.
                                                mc := end
                                            // Stop copying when the memory counter reaches the new combined
                                            // length of the arrays.
                                                end := add(mc, length)
                                                for {
                                                    let cc := add(_postBytes, 0x20)
                                                } lt(mc, end) {
                                                    mc := add(mc, 0x20)
                                                    cc := add(cc, 0x20)
                                                } {
                                                    mstore(mc, mload(cc))
                                                }
                                            // Update the free-memory pointer by padding our last write location
                                            // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
                                            // next 32 byte block, then round down to the nearest multiple of
                                            // 32. If the sum of the length of the two arrays is zero then add
                                            // one before rounding down to leave a blank 32 bytes (the length block with 0).
                                                mstore(0x40, and(
                                                add(add(end, iszero(add(length, mload(_preBytes)))), 31),
                                                not(31) // Round down to the nearest 32 bytes.
                                                ))
                                            }
                                            return tempBytes;
                                        }
                                        function concatStorage(bytes storage _preBytes, bytes memory _postBytes) internal {
                                            assembly {
                                            // Read the first 32 bytes of _preBytes storage, which is the length
                                            // of the array. (We don't need to use the offset into the slot
                                            // because arrays use the entire slot.)
                                                let fslot := sload(_preBytes.slot)
                                            // Arrays of 31 bytes or less have an even value in their slot,
                                            // while longer arrays have an odd value. The actual length is
                                            // the slot divided by two for odd values, and the lowest order
                                            // byte divided by two for even values.
                                            // If the slot is even, bitwise and the slot with 255 and divide by
                                            // two to get the length. If the slot is odd, bitwise and the slot
                                            // with -1 and divide by two.
                                                let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                                                let mlength := mload(_postBytes)
                                                let newlength := add(slength, mlength)
                                            // slength can contain both the length and contents of the array
                                            // if length < 32 bytes so let's prepare for that
                                            // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                                                switch add(lt(slength, 32), lt(newlength, 32))
                                                case 2 {
                                                // Since the new array still fits in the slot, we just need to
                                                // update the contents of the slot.
                                                // uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_length
                                                    sstore(
                                                    _preBytes.slot,
                                                    // all the modifications to the slot are inside this
                                                    // next block
                                                    add(
                                                    // we can just add to the slot contents because the
                                                    // bytes we want to change are the LSBs
                                                    fslot,
                                                    add(
                                                    mul(
                                                    div(
                                                    // load the bytes from memory
                                                    mload(add(_postBytes, 0x20)),
                                                    // zero all bytes to the right
                                                    exp(0x100, sub(32, mlength))
                                                    ),
                                                    // and now shift left the number of bytes to
                                                    // leave space for the length in the slot
                                                    exp(0x100, sub(32, newlength))
                                                    ),
                                                    // increase length by the double of the memory
                                                    // bytes length
                                                    mul(mlength, 2)
                                                    )
                                                    )
                                                    )
                                                }
                                                case 1 {
                                                // The stored value fits in the slot, but the combined value
                                                // will exceed it.
                                                // get the keccak hash to get the contents of the array
                                                    mstore(0x0, _preBytes.slot)
                                                    let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                                                // save new length
                                                    sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                                                // The contents of the _postBytes array start 32 bytes into
                                                // the structure. Our first read should obtain the `submod`
                                                // bytes that can fit into the unused space in the last word
                                                // of the stored array. To get this, we read 32 bytes starting
                                                // from `submod`, so the data we read overlaps with the array
                                                // contents by `submod` bytes. Masking the lowest-order
                                                // `submod` bytes allows us to add that value directly to the
                                                // stored value.
                                                    let submod := sub(32, slength)
                                                    let mc := add(_postBytes, submod)
                                                    let end := add(_postBytes, mlength)
                                                    let mask := sub(exp(0x100, submod), 1)
                                                    sstore(
                                                    sc,
                                                    add(
                                                    and(
                                                    fslot,
                                                    0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
                                                    ),
                                                    and(mload(mc), mask)
                                                    )
                                                    )
                                                    for {
                                                        mc := add(mc, 0x20)
                                                        sc := add(sc, 1)
                                                    } lt(mc, end) {
                                                        sc := add(sc, 1)
                                                        mc := add(mc, 0x20)
                                                    } {
                                                        sstore(sc, mload(mc))
                                                    }
                                                    mask := exp(0x100, sub(mc, end))
                                                    sstore(sc, mul(div(mload(mc), mask), mask))
                                                }
                                                default {
                                                // get the keccak hash to get the contents of the array
                                                    mstore(0x0, _preBytes.slot)
                                                // Start copying to the last used word of the stored array.
                                                    let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                                                // save new length
                                                    sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                                                // Copy over the first `submod` bytes of the new data as in
                                                // case 1 above.
                                                    let slengthmod := mod(slength, 32)
                                                    let mlengthmod := mod(mlength, 32)
                                                    let submod := sub(32, slengthmod)
                                                    let mc := add(_postBytes, submod)
                                                    let end := add(_postBytes, mlength)
                                                    let mask := sub(exp(0x100, submod), 1)
                                                    sstore(sc, add(sload(sc), and(mload(mc), mask)))
                                                    for {
                                                        sc := add(sc, 1)
                                                        mc := add(mc, 0x20)
                                                    } lt(mc, end) {
                                                        sc := add(sc, 1)
                                                        mc := add(mc, 0x20)
                                                    } {
                                                        sstore(sc, mload(mc))
                                                    }
                                                    mask := exp(0x100, sub(mc, end))
                                                    sstore(sc, mul(div(mload(mc), mask), mask))
                                                }
                                            }
                                        }
                                        function slice(
                                            bytes memory _bytes,
                                            uint256 _start,
                                            uint256 _length
                                        )
                                        internal
                                        pure
                                        returns (bytes memory)
                                        {
                                            require(_length + 31 >= _length, "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 toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
                                            require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
                                            address tempAddress;
                                            assembly {
                                                tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
                                            }
                                            return tempAddress;
                                        }
                                        function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
                                            require(_bytes.length >= _start + 1 , "toUint8_outOfBounds");
                                            uint8 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x1), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
                                            require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
                                            uint16 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x2), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint32(bytes memory _bytes, uint256 _start) internal pure returns (uint32) {
                                            require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
                                            uint32 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x4), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint64(bytes memory _bytes, uint256 _start) internal pure returns (uint64) {
                                            require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
                                            uint64 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x8), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint96(bytes memory _bytes, uint256 _start) internal pure returns (uint96) {
                                            require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
                                            uint96 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0xc), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint128(bytes memory _bytes, uint256 _start) internal pure returns (uint128) {
                                            require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
                                            uint128 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x10), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
                                            require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
                                            uint256 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x20), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
                                            require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
                                            bytes32 tempBytes32;
                                            assembly {
                                                tempBytes32 := mload(add(add(_bytes, 0x20), _start))
                                            }
                                            return tempBytes32;
                                        }
                                        function equal(bytes memory _preBytes, bytes memory _postBytes) internal pure returns (bool) {
                                            bool success = true;
                                            assembly {
                                                let length := mload(_preBytes)
                                            // if lengths don't match the arrays are not equal
                                                switch eq(length, mload(_postBytes))
                                                case 1 {
                                                // cb is a circuit breaker in the for loop since there's
                                                //  no said feature for inline assembly loops
                                                // cb = 1 - don't breaker
                                                // cb = 0 - break
                                                    let cb := 1
                                                    let mc := add(_preBytes, 0x20)
                                                    let end := add(mc, length)
                                                    for {
                                                        let cc := add(_postBytes, 0x20)
                                                    // the next line is the loop condition:
                                                    // while(uint256(mc < end) + cb == 2)
                                                    } eq(add(lt(mc, end), cb), 2) {
                                                        mc := add(mc, 0x20)
                                                        cc := add(cc, 0x20)
                                                    } {
                                                    // if any of these checks fails then arrays are not equal
                                                        if iszero(eq(mload(mc), mload(cc))) {
                                                        // unsuccess:
                                                            success := 0
                                                            cb := 0
                                                        }
                                                    }
                                                }
                                                default {
                                                // unsuccess:
                                                    success := 0
                                                }
                                            }
                                            return success;
                                        }
                                        function equalStorage(
                                            bytes storage _preBytes,
                                            bytes memory _postBytes
                                        )
                                        internal
                                        view
                                        returns (bool)
                                        {
                                            bool success = true;
                                            assembly {
                                            // we know _preBytes_offset is 0
                                                let fslot := sload(_preBytes.slot)
                                            // Decode the length of the stored array like in concatStorage().
                                                let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                                                let mlength := mload(_postBytes)
                                            // if lengths don't match the arrays are not equal
                                                switch eq(slength, mlength)
                                                case 1 {
                                                // slength can contain both the length and contents of the array
                                                // if length < 32 bytes so let's prepare for that
                                                // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                                                    if iszero(iszero(slength)) {
                                                        switch lt(slength, 32)
                                                        case 1 {
                                                        // blank the last byte which is the length
                                                            fslot := mul(div(fslot, 0x100), 0x100)
                                                            if iszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
                                                            // unsuccess:
                                                                success := 0
                                                            }
                                                        }
                                                        default {
                                                        // cb is a circuit breaker in the for loop since there's
                                                        //  no said feature for inline assembly loops
                                                        // cb = 1 - don't breaker
                                                        // cb = 0 - break
                                                            let cb := 1
                                                        // get the keccak hash to get the contents of the array
                                                            mstore(0x0, _preBytes.slot)
                                                            let sc := keccak256(0x0, 0x20)
                                                            let mc := add(_postBytes, 0x20)
                                                            let end := add(mc, mlength)
                                                        // the next line is the loop condition:
                                                        // while(uint256(mc < end) + cb == 2)
                                                            for {} eq(add(lt(mc, end), cb), 2) {
                                                                sc := add(sc, 1)
                                                                mc := add(mc, 0x20)
                                                            } {
                                                                if iszero(eq(sload(sc), mload(mc))) {
                                                                // unsuccess:
                                                                    success := 0
                                                                    cb := 0
                                                                }
                                                            }
                                                        }
                                                    }
                                                }
                                                default {
                                                // unsuccess:
                                                    success := 0
                                                }
                                            }
                                            return success;
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.8.0;
                                    import "@openzeppelin/contracts/access/Ownable.sol";
                                    import "../interfaces/ILayerZeroReceiver.sol";
                                    import "../interfaces/ILayerZeroUserApplicationConfig.sol";
                                    import "../interfaces/ILayerZeroEndpoint.sol";
                                    import "../util/BytesLib.sol";
                                    /*
                                     * a generic LzReceiver implementation
                                     */
                                    abstract contract LzApp is Ownable, ILayerZeroReceiver, ILayerZeroUserApplicationConfig {
                                        using BytesLib for bytes;
                                        ILayerZeroEndpoint public immutable lzEndpoint;
                                        mapping(uint16 => bytes) public trustedRemoteLookup;
                                        mapping(uint16 => mapping(uint16 => uint)) public minDstGasLookup;
                                        address public precrime;
                                        event SetPrecrime(address precrime);
                                        event SetTrustedRemote(uint16 _remoteChainId, bytes _path);
                                        event SetTrustedRemoteAddress(uint16 _remoteChainId, bytes _remoteAddress);
                                        event SetMinDstGas(uint16 _dstChainId, uint16 _type, uint _minDstGas);
                                        constructor(address _endpoint) {
                                            lzEndpoint = ILayerZeroEndpoint(_endpoint);
                                        }
                                        function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) public virtual override {
                                            // lzReceive must be called by the endpoint for security
                                            require(_msgSender() == address(lzEndpoint), "LzApp: invalid endpoint caller");
                                            bytes memory trustedRemote = trustedRemoteLookup[_srcChainId];
                                            // if will still block the message pathway from (srcChainId, srcAddress). should not receive message from untrusted remote.
                                            require(_srcAddress.length == trustedRemote.length && trustedRemote.length > 0 && keccak256(_srcAddress) == keccak256(trustedRemote), "LzApp: invalid source sending contract");
                                            _blockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
                                        }
                                        // abstract function - the default behaviour of LayerZero is blocking. See: NonblockingLzApp if you dont need to enforce ordered messaging
                                        function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;
                                        function _lzSend(uint16 _dstChainId, bytes memory _payload, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams, uint _nativeFee) internal virtual {
                                            bytes memory trustedRemote = trustedRemoteLookup[_dstChainId];
                                            require(trustedRemote.length != 0, "LzApp: destination chain is not a trusted source");
                                            lzEndpoint.send{value: _nativeFee}(_dstChainId, trustedRemote, _payload, _refundAddress, _zroPaymentAddress, _adapterParams);
                                        }
                                        function _checkGasLimit(uint16 _dstChainId, uint16 _type, bytes memory _adapterParams, uint _extraGas) internal view virtual {
                                            uint providedGasLimit = _getGasLimit(_adapterParams);
                                            uint minGasLimit = minDstGasLookup[_dstChainId][_type] + _extraGas;
                                            require(minGasLimit > 0, "LzApp: minGasLimit not set");
                                            require(providedGasLimit >= minGasLimit, "LzApp: gas limit is too low");
                                        }
                                        function _getGasLimit(bytes memory _adapterParams) internal pure virtual returns (uint gasLimit) {
                                            require(_adapterParams.length >= 34, "LzApp: invalid adapterParams");
                                            assembly {
                                                gasLimit := mload(add(_adapterParams, 34))
                                            }
                                        }
                                        //---------------------------UserApplication config----------------------------------------
                                        function getConfig(uint16 _version, uint16 _chainId, address, uint _configType) external view returns (bytes memory) {
                                            return lzEndpoint.getConfig(_version, _chainId, address(this), _configType);
                                        }
                                        // generic config for LayerZero user Application
                                        function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external override onlyOwner {
                                            lzEndpoint.setConfig(_version, _chainId, _configType, _config);
                                        }
                                        function setSendVersion(uint16 _version) external override onlyOwner {
                                            lzEndpoint.setSendVersion(_version);
                                        }
                                        function setReceiveVersion(uint16 _version) external override onlyOwner {
                                            lzEndpoint.setReceiveVersion(_version);
                                        }
                                        function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external override onlyOwner {
                                            lzEndpoint.forceResumeReceive(_srcChainId, _srcAddress);
                                        }
                                        // _path = abi.encodePacked(remoteAddress, localAddress)
                                        // this function set the trusted path for the cross-chain communication
                                        function setTrustedRemote(uint16 _srcChainId, bytes calldata _path) external onlyOwner {
                                            trustedRemoteLookup[_srcChainId] = _path;
                                            emit SetTrustedRemote(_srcChainId, _path);
                                        }
                                        function setTrustedRemoteAddress(uint16 _remoteChainId, bytes calldata _remoteAddress) external onlyOwner {
                                            trustedRemoteLookup[_remoteChainId] = abi.encodePacked(_remoteAddress, address(this));
                                            emit SetTrustedRemoteAddress(_remoteChainId, _remoteAddress);
                                        }
                                        function getTrustedRemoteAddress(uint16 _remoteChainId) external view returns (bytes memory) {
                                            bytes memory path = trustedRemoteLookup[_remoteChainId];
                                            require(path.length != 0, "LzApp: no trusted path record");
                                            return path.slice(0, path.length - 20); // the last 20 bytes should be address(this)
                                        }
                                        function setPrecrime(address _precrime) external onlyOwner {
                                            precrime = _precrime;
                                            emit SetPrecrime(_precrime);
                                        }
                                        function setMinDstGas(uint16 _dstChainId, uint16 _packetType, uint _minGas) external onlyOwner {
                                            require(_minGas > 0, "LzApp: invalid minGas");
                                            minDstGasLookup[_dstChainId][_packetType] = _minGas;
                                            emit SetMinDstGas(_dstChainId, _packetType, _minGas);
                                        }
                                        //--------------------------- VIEW FUNCTION ----------------------------------------
                                        function isTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool) {
                                            bytes memory trustedSource = trustedRemoteLookup[_srcChainId];
                                            return keccak256(trustedSource) == keccak256(_srcAddress);
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.8.0;
                                    import "./LzApp.sol";
                                    import "../util/ExcessivelySafeCall.sol";
                                    /*
                                     * the default LayerZero messaging behaviour is blocking, i.e. any failed message will block the channel
                                     * this abstract class try-catch all fail messages and store locally for future retry. hence, non-blocking
                                     * NOTE: if the srcAddress is not configured properly, it will still block the message pathway from (srcChainId, srcAddress)
                                     */
                                    abstract contract NonblockingLzApp is LzApp {
                                        using ExcessivelySafeCall for address;
                                        constructor(address _endpoint) LzApp(_endpoint) {}
                                        mapping(uint16 => mapping(bytes => mapping(uint64 => bytes32))) public failedMessages;
                                        event MessageFailed(uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes _payload, bytes _reason);
                                        event RetryMessageSuccess(uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes32 _payloadHash);
                                        // overriding the virtual function in LzReceiver
                                        function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual override {
                                            (bool success, bytes memory reason) = address(this).excessivelySafeCall(gasleft(), 150, abi.encodeWithSelector(this.nonblockingLzReceive.selector, _srcChainId, _srcAddress, _nonce, _payload));
                                            // try-catch all errors/exceptions
                                            if (!success) {
                                                _storeFailedMessage(_srcChainId, _srcAddress, _nonce, _payload, reason);
                                            }
                                        }
                                        function _storeFailedMessage(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload, bytes memory _reason) internal virtual {
                                            failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(_payload);
                                            emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload, _reason);
                                        }
                                        function nonblockingLzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) public virtual {
                                            // only internal transaction
                                            require(_msgSender() == address(this), "NonblockingLzApp: caller must be LzApp");
                                            _nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
                                        }
                                        //@notice override this function
                                        function _nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;
                                        function retryMessage(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) public payable virtual {
                                            // assert there is message to retry
                                            bytes32 payloadHash = failedMessages[_srcChainId][_srcAddress][_nonce];
                                            require(payloadHash != bytes32(0), "NonblockingLzApp: no stored message");
                                            require(keccak256(_payload) == payloadHash, "NonblockingLzApp: invalid payload");
                                            // clear the stored message
                                            failedMessages[_srcChainId][_srcAddress][_nonce] = bytes32(0);
                                            // execute the message. revert if it fails again
                                            _nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
                                            emit RetryMessageSuccess(_srcChainId, _srcAddress, _nonce, payloadHash);
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT OR Apache-2.0
                                    pragma solidity >=0.7.6;
                                    library ExcessivelySafeCall {
                                        uint256 constant LOW_28_MASK =
                                        0x00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff;
                                        /// @notice Use when you _really_ really _really_ don't trust the called
                                        /// contract. This prevents the called contract from causing reversion of
                                        /// the caller in as many ways as we can.
                                        /// @dev The main difference between this and a solidity low-level call is
                                        /// that we limit the number of bytes that the callee can cause to be
                                        /// copied to caller memory. This prevents stupid things like malicious
                                        /// contracts returning 10,000,000 bytes causing a local OOG when copying
                                        /// to memory.
                                        /// @param _target The address to call
                                        /// @param _gas The amount of gas to forward to the remote contract
                                        /// @param _maxCopy The maximum number of bytes of returndata to copy
                                        /// to memory.
                                        /// @param _calldata The data to send to the remote contract
                                        /// @return success and returndata, as `.call()`. Returndata is capped to
                                        /// `_maxCopy` bytes.
                                        function excessivelySafeCall(
                                            address _target,
                                            uint256 _gas,
                                            uint16 _maxCopy,
                                            bytes memory _calldata
                                        ) internal returns (bool, bytes memory) {
                                            // set up for assembly call
                                            uint256 _toCopy;
                                            bool _success;
                                            bytes memory _returnData = new bytes(_maxCopy);
                                            // dispatch message to recipient
                                            // by assembly calling "handle" function
                                            // we call via assembly to avoid memcopying a very large returndata
                                            // returned by a malicious contract
                                            assembly {
                                                _success := call(
                                                _gas, // gas
                                                _target, // recipient
                                                0, // ether value
                                                add(_calldata, 0x20), // inloc
                                                mload(_calldata), // inlen
                                                0, // outloc
                                                0 // outlen
                                                )
                                            // limit our copy to 256 bytes
                                                _toCopy := returndatasize()
                                                if gt(_toCopy, _maxCopy) {
                                                    _toCopy := _maxCopy
                                                }
                                            // Store the length of the copied bytes
                                                mstore(_returnData, _toCopy)
                                            // copy the bytes from returndata[0:_toCopy]
                                                returndatacopy(add(_returnData, 0x20), 0, _toCopy)
                                            }
                                            return (_success, _returnData);
                                        }
                                        /// @notice Use when you _really_ really _really_ don't trust the called
                                        /// contract. This prevents the called contract from causing reversion of
                                        /// the caller in as many ways as we can.
                                        /// @dev The main difference between this and a solidity low-level call is
                                        /// that we limit the number of bytes that the callee can cause to be
                                        /// copied to caller memory. This prevents stupid things like malicious
                                        /// contracts returning 10,000,000 bytes causing a local OOG when copying
                                        /// to memory.
                                        /// @param _target The address to call
                                        /// @param _gas The amount of gas to forward to the remote contract
                                        /// @param _maxCopy The maximum number of bytes of returndata to copy
                                        /// to memory.
                                        /// @param _calldata The data to send to the remote contract
                                        /// @return success and returndata, as `.call()`. Returndata is capped to
                                        /// `_maxCopy` bytes.
                                        function excessivelySafeStaticCall(
                                            address _target,
                                            uint256 _gas,
                                            uint16 _maxCopy,
                                            bytes memory _calldata
                                        ) internal view returns (bool, bytes memory) {
                                            // set up for assembly call
                                            uint256 _toCopy;
                                            bool _success;
                                            bytes memory _returnData = new bytes(_maxCopy);
                                            // dispatch message to recipient
                                            // by assembly calling "handle" function
                                            // we call via assembly to avoid memcopying a very large returndata
                                            // returned by a malicious contract
                                            assembly {
                                                _success := staticcall(
                                                _gas, // gas
                                                _target, // recipient
                                                add(_calldata, 0x20), // inloc
                                                mload(_calldata), // inlen
                                                0, // outloc
                                                0 // outlen
                                                )
                                            // limit our copy to 256 bytes
                                                _toCopy := returndatasize()
                                                if gt(_toCopy, _maxCopy) {
                                                    _toCopy := _maxCopy
                                                }
                                            // Store the length of the copied bytes
                                                mstore(_returnData, _toCopy)
                                            // copy the bytes from returndata[0:_toCopy]
                                                returndatacopy(add(_returnData, 0x20), 0, _toCopy)
                                            }
                                            return (_success, _returnData);
                                        }
                                        /**
                                         * @notice Swaps function selectors in encoded contract calls
                                         * @dev Allows reuse of encoded calldata for functions with identical
                                         * argument types but different names. It simply swaps out the first 4 bytes
                                         * for the new selector. This function modifies memory in place, and should
                                         * only be used with caution.
                                         * @param _newSelector The new 4-byte selector
                                         * @param _buf The encoded contract args
                                         */
                                        function swapSelector(bytes4 _newSelector, bytes memory _buf)
                                        internal
                                        pure
                                        {
                                            require(_buf.length >= 4);
                                            uint256 _mask = LOW_28_MASK;
                                            assembly {
                                            // load the first word of
                                                let _word := mload(add(_buf, 0x20))
                                            // mask out the top 4 bytes
                                            // /x
                                                _word := and(_word, _mask)
                                                _word := or(_newSelector, _word)
                                                mstore(add(_buf, 0x20), _word)
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.5.0;
                                    interface IOFTReceiverV2 {
                                        /**
                                         * @dev Called by the OFT contract when tokens are received from source chain.
                                         * @param _srcChainId The chain id of the source chain.
                                         * @param _srcAddress The address of the OFT token contract on the source chain.
                                         * @param _nonce The nonce of the transaction on the source chain.
                                         * @param _from The address of the account who calls the sendAndCall() on the source chain.
                                         * @param _amount The amount of tokens to transfer.
                                         * @param _payload Additional data with no specified format.
                                         */
                                        function onOFTReceived(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes32 _from, uint _amount, bytes calldata _payload) external;
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.8.0;
                                    import "../../../lzApp/NonblockingLzApp.sol";
                                    import "../../../util/ExcessivelySafeCall.sol";
                                    import "./ICommonOFT.sol";
                                    import "./IOFTReceiverV2.sol";
                                    abstract contract OFTCoreV2 is NonblockingLzApp {
                                        using BytesLib for bytes;
                                        using ExcessivelySafeCall for address;
                                        uint public constant NO_EXTRA_GAS = 0;
                                        // packet type
                                        uint8 public constant PT_SEND = 0;
                                        uint8 public constant PT_SEND_AND_CALL = 1;
                                        uint8 public immutable sharedDecimals;
                                        bool public useCustomAdapterParams;
                                        mapping(uint16 => mapping(bytes => mapping(uint64 => bool))) public creditedPackets;
                                        /**
                                         * @dev Emitted when `_amount` tokens are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
                                         * `_nonce` is the outbound nonce
                                         */
                                        event SendToChain(uint16 indexed _dstChainId, address indexed _from, bytes32 indexed _toAddress, uint _amount);
                                        /**
                                         * @dev Emitted when `_amount` tokens are received from `_srcChainId` into the `_toAddress` on the local chain.
                                         * `_nonce` is the inbound nonce.
                                         */
                                        event ReceiveFromChain(uint16 indexed _srcChainId, address indexed _to, uint _amount);
                                        event SetUseCustomAdapterParams(bool _useCustomAdapterParams);
                                        event CallOFTReceivedSuccess(uint16 indexed _srcChainId, bytes _srcAddress, uint64 _nonce, bytes32 _hash);
                                        event NonContractAddress(address _address);
                                        // _sharedDecimals should be the minimum decimals on all chains
                                        constructor(uint8 _sharedDecimals, address _lzEndpoint) NonblockingLzApp(_lzEndpoint) {
                                            sharedDecimals = _sharedDecimals;
                                        }
                                        /************************************************************************
                                        * public functions
                                        ************************************************************************/
                                        function callOnOFTReceived(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes32 _from, address _to, uint _amount, bytes calldata _payload, uint _gasForCall) public virtual {
                                            require(_msgSender() == address(this), "OFTCore: caller must be OFTCore");
                                            // send
                                            _amount = _transferFrom(address(this), _to, _amount);
                                            emit ReceiveFromChain(_srcChainId, _to, _amount);
                                            // call
                                            IOFTReceiverV2(_to).onOFTReceived{gas: _gasForCall}(_srcChainId, _srcAddress, _nonce, _from, _amount, _payload);
                                        }
                                        function setUseCustomAdapterParams(bool _useCustomAdapterParams) public virtual onlyOwner {
                                            useCustomAdapterParams = _useCustomAdapterParams;
                                            emit SetUseCustomAdapterParams(_useCustomAdapterParams);
                                        }
                                        /************************************************************************
                                        * internal functions
                                        ************************************************************************/
                                        function _estimateSendFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bool _useZro, bytes memory _adapterParams) internal view virtual returns (uint nativeFee, uint zroFee) {
                                            // mock the payload for sendFrom()
                                            bytes memory payload = _encodeSendPayload(_toAddress, _ld2sd(_amount));
                                            return lzEndpoint.estimateFees(_dstChainId, address(this), payload, _useZro, _adapterParams);
                                        }
                                        function _estimateSendAndCallFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes memory _payload, uint64 _dstGasForCall, bool _useZro, bytes memory _adapterParams) internal view virtual returns (uint nativeFee, uint zroFee) {
                                            // mock the payload for sendAndCall()
                                            bytes memory payload = _encodeSendAndCallPayload(msg.sender, _toAddress, _ld2sd(_amount), _payload, _dstGasForCall);
                                            return lzEndpoint.estimateFees(_dstChainId, address(this), payload, _useZro, _adapterParams);
                                        }
                                        function _nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual override {
                                            uint8 packetType = _payload.toUint8(0);
                                            if (packetType == PT_SEND) {
                                                _sendAck(_srcChainId, _srcAddress, _nonce, _payload);
                                            } else if (packetType == PT_SEND_AND_CALL) {
                                                _sendAndCallAck(_srcChainId, _srcAddress, _nonce, _payload);
                                            } else {
                                                revert("OFTCore: unknown packet type");
                                            }
                                        }
                                        function _send(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams) internal virtual returns (uint amount) {
                                            _checkAdapterParams(_dstChainId, PT_SEND, _adapterParams, NO_EXTRA_GAS);
                                            (amount,) = _removeDust(_amount);
                                            amount = _debitFrom(_from, _dstChainId, _toAddress, amount); // amount returned should not have dust
                                            require(amount > 0, "OFTCore: amount too small");
                                            bytes memory lzPayload = _encodeSendPayload(_toAddress, _ld2sd(amount));
                                            _lzSend(_dstChainId, lzPayload, _refundAddress, _zroPaymentAddress, _adapterParams, msg.value);
                                            emit SendToChain(_dstChainId, _from, _toAddress, amount);
                                        }
                                        function _sendAck(uint16 _srcChainId, bytes memory, uint64, bytes memory _payload) internal virtual {
                                            (address to, uint64 amountSD) = _decodeSendPayload(_payload);
                                            if (to == address(0)) {
                                                to = address(0xdead);
                                            }
                                            uint amount = _sd2ld(amountSD);
                                            amount = _creditTo(_srcChainId, to, amount);
                                            emit ReceiveFromChain(_srcChainId, to, amount);
                                        }
                                        function _sendAndCall(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes memory _payload, uint64 _dstGasForCall, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams) internal virtual returns (uint amount) {
                                            _checkAdapterParams(_dstChainId, PT_SEND_AND_CALL, _adapterParams, _dstGasForCall);
                                            (amount,) = _removeDust(_amount);
                                            amount = _debitFrom(_from, _dstChainId, _toAddress, amount);
                                            require(amount > 0, "OFTCore: amount too small");
                                            // encode the msg.sender into the payload instead of _from
                                            bytes memory lzPayload = _encodeSendAndCallPayload(msg.sender, _toAddress, _ld2sd(amount), _payload, _dstGasForCall);
                                            _lzSend(_dstChainId, lzPayload, _refundAddress, _zroPaymentAddress, _adapterParams, msg.value);
                                            emit SendToChain(_dstChainId, _from, _toAddress, amount);
                                        }
                                        function _sendAndCallAck(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual {
                                            (bytes32 from, address to, uint64 amountSD, bytes memory payloadForCall, uint64 gasForCall) = _decodeSendAndCallPayload(_payload);
                                            bool credited = creditedPackets[_srcChainId][_srcAddress][_nonce];
                                            uint amount = _sd2ld(amountSD);
                                            // credit to this contract first, and then transfer to receiver only if callOnOFTReceived() succeeds
                                            if (!credited) {
                                                amount = _creditTo(_srcChainId, address(this), amount);
                                                creditedPackets[_srcChainId][_srcAddress][_nonce] = true;
                                            }
                                            if (!_isContract(to)) {
                                                emit NonContractAddress(to);
                                                return;
                                            }
                                            // workaround for stack too deep
                                            uint16 srcChainId = _srcChainId;
                                            bytes memory srcAddress = _srcAddress;
                                            uint64 nonce = _nonce;
                                            bytes memory payload = _payload;
                                            bytes32 from_ = from;
                                            address to_ = to;
                                            uint amount_ = amount;
                                            bytes memory payloadForCall_ = payloadForCall;
                                            // no gas limit for the call if retry
                                            uint gas = credited ? gasleft() : gasForCall;
                                            (bool success, bytes memory reason) = address(this).excessivelySafeCall(gasleft(), 150, abi.encodeWithSelector(this.callOnOFTReceived.selector, srcChainId, srcAddress, nonce, from_, to_, amount_, payloadForCall_, gas));
                                            if (success) {
                                                bytes32 hash = keccak256(payload);
                                                emit CallOFTReceivedSuccess(srcChainId, srcAddress, nonce, hash);
                                            } else {
                                                // store the failed message into the nonblockingLzApp
                                                _storeFailedMessage(srcChainId, srcAddress, nonce, payload, reason);
                                            }
                                        }
                                        function _isContract(address _account) internal view returns (bool) {
                                            return _account.code.length > 0;
                                        }
                                        function _checkAdapterParams(uint16 _dstChainId, uint16 _pkType, bytes memory _adapterParams, uint _extraGas) internal virtual {
                                            if (useCustomAdapterParams) {
                                                _checkGasLimit(_dstChainId, _pkType, _adapterParams, _extraGas);
                                            } else {
                                                require(_adapterParams.length == 0, "OFTCore: _adapterParams must be empty.");
                                            }
                                        }
                                        function _ld2sd(uint _amount) internal virtual view returns (uint64) {
                                            uint amountSD = _amount / _ld2sdRate();
                                            require(amountSD <= type(uint64).max, "OFTCore: amountSD overflow");
                                            return uint64(amountSD);
                                        }
                                        function _sd2ld(uint64 _amountSD) internal virtual view returns (uint) {
                                            return _amountSD * _ld2sdRate();
                                        }
                                        function _removeDust(uint _amount) internal virtual view returns (uint amountAfter, uint dust) {
                                            dust = _amount % _ld2sdRate();
                                            amountAfter = _amount - dust;
                                        }
                                        function _encodeSendPayload(bytes32 _toAddress, uint64 _amountSD) internal virtual view returns (bytes memory) {
                                            return abi.encodePacked(PT_SEND, _toAddress, _amountSD);
                                        }
                                        function _decodeSendPayload(bytes memory _payload) internal virtual view returns (address to, uint64 amountSD) {
                                            require(_payload.toUint8(0) == PT_SEND && _payload.length == 41, "OFTCore: invalid payload");
                                            to = _payload.toAddress(13); // drop the first 12 bytes of bytes32
                                            amountSD = _payload.toUint64(33);
                                        }
                                        function _encodeSendAndCallPayload(address _from, bytes32 _toAddress, uint64 _amountSD, bytes memory _payload, uint64 _dstGasForCall) internal virtual view returns (bytes memory) {
                                            return abi.encodePacked(
                                                PT_SEND_AND_CALL,
                                                _toAddress,
                                                _amountSD,
                                                _addressToBytes32(_from),
                                                _dstGasForCall,
                                                _payload
                                            );
                                        }
                                        function _decodeSendAndCallPayload(bytes memory _payload) internal virtual view returns (bytes32 from, address to, uint64 amountSD, bytes memory payload, uint64 dstGasForCall) {
                                            require(_payload.toUint8(0) == PT_SEND_AND_CALL, "OFTCore: invalid payload");
                                            to = _payload.toAddress(13); // drop the first 12 bytes of bytes32
                                            amountSD = _payload.toUint64(33);
                                            from = _payload.toBytes32(41);
                                            dstGasForCall = _payload.toUint64(73);
                                            payload = _payload.slice(81, _payload.length - 81);
                                        }
                                        function _addressToBytes32(address _address) internal pure virtual returns (bytes32) {
                                            return bytes32(uint(uint160(_address)));
                                        }
                                        function _debitFrom(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount) internal virtual returns (uint);
                                        function _creditTo(uint16 _srcChainId, address _toAddress, uint _amount) internal virtual returns (uint);
                                        function _transferFrom(address _from, address _to, uint _amount) internal virtual returns (uint);
                                        function _ld2sdRate() internal view virtual returns (uint);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity >=0.5.0;
                                    import "./ICommonOFT.sol";
                                    /**
                                     * @dev Interface of the IOFT core standard
                                     */
                                    interface IOFTV2 is ICommonOFT {
                                        /**
                                         * @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
                                         * `_from` the owner of token
                                         * `_dstChainId` the destination chain identifier
                                         * `_toAddress` can be any size depending on the `dstChainId`.
                                         * `_amount` the quantity of tokens in wei
                                         * `_refundAddress` the address LayerZero refunds if too much message fee is sent
                                         * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
                                         * `_adapterParams` is a flexible bytes array to indicate messaging adapter services
                                         */
                                        function sendFrom(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, LzCallParams calldata _callParams) external payable;
                                        function sendAndCall(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, LzCallParams calldata _callParams) external payable;
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
                                    pragma solidity ^0.8.0;
                                    import "./IERC165.sol";
                                    /**
                                     * @dev Implementation of the {IERC165} interface.
                                     *
                                     * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
                                     * for the additional interface id that will be supported. For example:
                                     *
                                     * ```solidity
                                     * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                                     *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
                                     * }
                                     * ```
                                     *
                                     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
                                     */
                                    abstract contract ERC165 is IERC165 {
                                        /**
                                         * @dev See {IERC165-supportsInterface}.
                                         */
                                        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                                            return interfaceId == type(IERC165).interfaceId;
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.8.0;
                                    import "./OFTCoreV2.sol";
                                    import "./IOFTV2.sol";
                                    import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
                                    abstract contract BaseOFTV2 is OFTCoreV2, ERC165, IOFTV2 {
                                        constructor(uint8 _sharedDecimals, address _lzEndpoint) OFTCoreV2(_sharedDecimals, _lzEndpoint) {
                                        }
                                        /************************************************************************
                                        * public functions
                                        ************************************************************************/
                                        function sendFrom(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, LzCallParams calldata _callParams) public payable virtual override {
                                            _send(_from, _dstChainId, _toAddress, _amount, _callParams.refundAddress, _callParams.zroPaymentAddress, _callParams.adapterParams);
                                        }
                                        function sendAndCall(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, LzCallParams calldata _callParams) public payable virtual override {
                                            _sendAndCall(_from, _dstChainId, _toAddress, _amount, _payload, _dstGasForCall, _callParams.refundAddress, _callParams.zroPaymentAddress, _callParams.adapterParams);
                                        }
                                        /************************************************************************
                                        * public view functions
                                        ************************************************************************/
                                        function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
                                            return interfaceId == type(IOFTV2).interfaceId || super.supportsInterface(interfaceId);
                                        }
                                        function estimateSendFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) public view virtual override returns (uint nativeFee, uint zroFee) {
                                            return _estimateSendFee(_dstChainId, _toAddress, _amount, _useZro, _adapterParams);
                                        }
                                        function estimateSendAndCallFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, bool _useZro, bytes calldata _adapterParams) public view virtual override returns (uint nativeFee, uint zroFee) {
                                            return _estimateSendAndCallFee(_dstChainId, _toAddress, _amount, _payload, _dstGasForCall, _useZro, _adapterParams);
                                        }
                                        function circulatingSupply() public view virtual override returns (uint);
                                        function token() public view virtual override returns (address);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)
                                    pragma solidity ^0.8.0;
                                    import "../IERC20.sol";
                                    import "../extensions/draft-IERC20Permit.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));
                                            }
                                        }
                                        function safePermit(
                                            IERC20Permit token,
                                            address owner,
                                            address spender,
                                            uint256 value,
                                            uint256 deadline,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) internal {
                                            uint256 nonceBefore = token.nonces(owner);
                                            token.permit(owner, spender, value, deadline, v, r, s);
                                            uint256 nonceAfter = token.nonces(owner);
                                            require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
                                        }
                                        /**
                                         * @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
                                    pragma solidity ^0.8.0;
                                    import "./BaseOFTV2.sol";
                                    import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
                                    contract ProxyOFTV2 is BaseOFTV2 {
                                        using SafeERC20 for IERC20;
                                        IERC20 internal immutable innerToken;
                                        uint internal immutable ld2sdRate;
                                        // total amount is transferred from this chain to other chains, ensuring the total is less than uint64.max in sd
                                        uint public outboundAmount;
                                        constructor(address _token, uint8 _sharedDecimals, address _lzEndpoint) BaseOFTV2(_sharedDecimals, _lzEndpoint) {
                                            innerToken = IERC20(_token);
                                            (bool success, bytes memory data) = _token.staticcall(
                                                abi.encodeWithSignature("decimals()")
                                            );
                                            require(success, "ProxyOFT: failed to get token decimals");
                                            uint8 decimals = abi.decode(data, (uint8));
                                            require(_sharedDecimals <= decimals, "ProxyOFT: sharedDecimals must be <= decimals");
                                            ld2sdRate = 10 ** (decimals - _sharedDecimals);
                                        }
                                        /************************************************************************
                                        * public functions
                                        ************************************************************************/
                                        function circulatingSupply() public view virtual override returns (uint) {
                                            return innerToken.totalSupply() - outboundAmount;
                                        }
                                        function token() public view virtual override returns (address) {
                                            return address(innerToken);
                                        }
                                        /************************************************************************
                                        * internal functions
                                        ************************************************************************/
                                        function _debitFrom(address _from, uint16, bytes32, uint _amount) internal virtual override returns (uint) {
                                            require(_from == _msgSender(), "ProxyOFT: owner is not send caller");
                                            _amount = _transferFrom(_from, address(this), _amount);
                                            // _amount still may have dust if the token has transfer fee, then give the dust back to the sender
                                            (uint amount, uint dust) = _removeDust(_amount);
                                            if (dust > 0) innerToken.safeTransfer(_from, dust);
                                            // check total outbound amount
                                            outboundAmount += amount;
                                            uint cap = _sd2ld(type(uint64).max);
                                            require(cap >= outboundAmount, "ProxyOFT: outboundAmount overflow");
                                            return amount;
                                        }
                                        function _creditTo(uint16, address _toAddress, uint _amount) internal virtual override returns (uint) {
                                            outboundAmount -= _amount;
                                            // tokens are already in this contract, so no need to transfer
                                            if (_toAddress == address(this)) {
                                                return _amount;
                                            }
                                            return _transferFrom(address(this), _toAddress, _amount);
                                        }
                                        function _transferFrom(address _from, address _to, uint _amount) internal virtual override returns (uint) {
                                            uint before = innerToken.balanceOf(_to);
                                            if (_from == address(this)) {
                                                innerToken.safeTransfer(_to, _amount);
                                            } else {
                                                innerToken.safeTransferFrom(_from, _to, _amount);
                                            }
                                            return innerToken.balanceOf(_to) - before;
                                        }
                                        function _ld2sdRate() internal view virtual override returns (uint) {
                                            return ld2sdRate;
                                        }
                                    }
                                    

                                    File 7 of 12: FiatTokenV2_1
                                    // File: @openzeppelin/contracts/math/SafeMath.sol
                                    
                                    // SPDX-License-Identifier: MIT
                                    
                                    pragma solidity ^0.6.0;
                                    
                                    /**
                                     * @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, 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) {
                                            return sub(a, b, "SafeMath: subtraction overflow");
                                        }
                                    
                                        /**
                                         * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
                                         * overflow (when the result is negative).
                                         *
                                         * 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);
                                            uint256 c = a - b;
                                    
                                            return c;
                                        }
                                    
                                        /**
                                         * @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) {
                                            // 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 0;
                                            }
                                    
                                            uint256 c = a * b;
                                            require(c / a == b, "SafeMath: multiplication overflow");
                                    
                                            return c;
                                        }
                                    
                                        /**
                                         * @dev Returns the integer division of two unsigned integers. Reverts 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) {
                                            return div(a, b, "SafeMath: division by zero");
                                        }
                                    
                                        /**
                                         * @dev Returns the integer division of two unsigned integers. Reverts with custom message 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,
                                            string memory errorMessage
                                        ) internal pure returns (uint256) {
                                            require(b > 0, errorMessage);
                                            uint256 c = a / b;
                                            // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                                    
                                            return c;
                                        }
                                    
                                        /**
                                         * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                                         * Reverts 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) {
                                            return mod(a, b, "SafeMath: modulo by zero");
                                        }
                                    
                                        /**
                                         * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                                         * Reverts with custom message 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,
                                            string memory errorMessage
                                        ) internal pure returns (uint256) {
                                            require(b != 0, errorMessage);
                                            return a % b;
                                        }
                                    }
                                    
                                    // File: @openzeppelin/contracts/token/ERC20/IERC20.sol
                                    
                                    pragma solidity ^0.6.0;
                                    
                                    /**
                                     * @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
                                        );
                                    }
                                    
                                    // File: contracts/v1/AbstractFiatTokenV1.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    abstract contract AbstractFiatTokenV1 is IERC20 {
                                        function _approve(
                                            address owner,
                                            address spender,
                                            uint256 value
                                        ) internal virtual;
                                    
                                        function _transfer(
                                            address from,
                                            address to,
                                            uint256 value
                                        ) internal virtual;
                                    }
                                    
                                    // File: contracts/v1/Ownable.sol
                                    
                                    /**
                                     * Copyright (c) 2018 zOS Global Limited.
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @notice The Ownable contract has an owner address, and provides basic
                                     * authorization control functions
                                     * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-labs/blob/3887ab77b8adafba4a26ace002f3a684c1a3388b/upgradeability_ownership/contracts/ownership/Ownable.sol
                                     * Modifications:
                                     * 1. Consolidate OwnableStorage into this contract (7/13/18)
                                     * 2. Reformat, conform to Solidity 0.6 syntax, and add error messages (5/13/20)
                                     * 3. Make public functions external (5/27/20)
                                     */
                                    contract Ownable {
                                        // Owner of the contract
                                        address private _owner;
                                    
                                        /**
                                         * @dev Event to show ownership has been transferred
                                         * @param previousOwner representing the address of the previous owner
                                         * @param newOwner representing the address of the new owner
                                         */
                                        event OwnershipTransferred(address previousOwner, address newOwner);
                                    
                                        /**
                                         * @dev The constructor sets the original owner of the contract to the sender account.
                                         */
                                        constructor() public {
                                            setOwner(msg.sender);
                                        }
                                    
                                        /**
                                         * @dev Tells the address of the owner
                                         * @return the address of the owner
                                         */
                                        function owner() external view returns (address) {
                                            return _owner;
                                        }
                                    
                                        /**
                                         * @dev Sets a new owner address
                                         */
                                        function setOwner(address newOwner) internal {
                                            _owner = newOwner;
                                        }
                                    
                                        /**
                                         * @dev Throws if called by any account other than the owner.
                                         */
                                        modifier onlyOwner() {
                                            require(msg.sender == _owner, "Ownable: caller is not the owner");
                                            _;
                                        }
                                    
                                        /**
                                         * @dev Allows the current owner to transfer control of the contract to a newOwner.
                                         * @param newOwner The address to transfer ownership to.
                                         */
                                        function transferOwnership(address newOwner) external onlyOwner {
                                            require(
                                                newOwner != address(0),
                                                "Ownable: new owner is the zero address"
                                            );
                                            emit OwnershipTransferred(_owner, newOwner);
                                            setOwner(newOwner);
                                        }
                                    }
                                    
                                    // File: contracts/v1/Pausable.sol
                                    
                                    /**
                                     * Copyright (c) 2016 Smart Contract Solutions, Inc.
                                     * Copyright (c) 2018-2020 CENTRE SECZ0
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @notice Base contract which allows children to implement an emergency stop
                                     * mechanism
                                     * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/feb665136c0dae9912e08397c1a21c4af3651ef3/contracts/lifecycle/Pausable.sol
                                     * Modifications:
                                     * 1. Added pauser role, switched pause/unpause to be onlyPauser (6/14/2018)
                                     * 2. Removed whenNotPause/whenPaused from pause/unpause (6/14/2018)
                                     * 3. Removed whenPaused (6/14/2018)
                                     * 4. Switches ownable library to use ZeppelinOS (7/12/18)
                                     * 5. Remove constructor (7/13/18)
                                     * 6. Reformat, conform to Solidity 0.6 syntax and add error messages (5/13/20)
                                     * 7. Make public functions external (5/27/20)
                                     */
                                    contract Pausable is Ownable {
                                        event Pause();
                                        event Unpause();
                                        event PauserChanged(address indexed newAddress);
                                    
                                        address public pauser;
                                        bool public paused = false;
                                    
                                        /**
                                         * @dev Modifier to make a function callable only when the contract is not paused.
                                         */
                                        modifier whenNotPaused() {
                                            require(!paused, "Pausable: paused");
                                            _;
                                        }
                                    
                                        /**
                                         * @dev throws if called by any account other than the pauser
                                         */
                                        modifier onlyPauser() {
                                            require(msg.sender == pauser, "Pausable: caller is not the pauser");
                                            _;
                                        }
                                    
                                        /**
                                         * @dev called by the owner to pause, triggers stopped state
                                         */
                                        function pause() external onlyPauser {
                                            paused = true;
                                            emit Pause();
                                        }
                                    
                                        /**
                                         * @dev called by the owner to unpause, returns to normal state
                                         */
                                        function unpause() external onlyPauser {
                                            paused = false;
                                            emit Unpause();
                                        }
                                    
                                        /**
                                         * @dev update the pauser role
                                         */
                                        function updatePauser(address _newPauser) external onlyOwner {
                                            require(
                                                _newPauser != address(0),
                                                "Pausable: new pauser is the zero address"
                                            );
                                            pauser = _newPauser;
                                            emit PauserChanged(pauser);
                                        }
                                    }
                                    
                                    // File: contracts/v1/Blacklistable.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @title Blacklistable Token
                                     * @dev Allows accounts to be blacklisted by a "blacklister" role
                                     */
                                    contract Blacklistable is Ownable {
                                        address public blacklister;
                                        mapping(address => bool) internal blacklisted;
                                    
                                        event Blacklisted(address indexed _account);
                                        event UnBlacklisted(address indexed _account);
                                        event BlacklisterChanged(address indexed newBlacklister);
                                    
                                        /**
                                         * @dev Throws if called by any account other than the blacklister
                                         */
                                        modifier onlyBlacklister() {
                                            require(
                                                msg.sender == blacklister,
                                                "Blacklistable: caller is not the blacklister"
                                            );
                                            _;
                                        }
                                    
                                        /**
                                         * @dev Throws if argument account is blacklisted
                                         * @param _account The address to check
                                         */
                                        modifier notBlacklisted(address _account) {
                                            require(
                                                !blacklisted[_account],
                                                "Blacklistable: account is blacklisted"
                                            );
                                            _;
                                        }
                                    
                                        /**
                                         * @dev Checks if account is blacklisted
                                         * @param _account The address to check
                                         */
                                        function isBlacklisted(address _account) external view returns (bool) {
                                            return blacklisted[_account];
                                        }
                                    
                                        /**
                                         * @dev Adds account to blacklist
                                         * @param _account The address to blacklist
                                         */
                                        function blacklist(address _account) external onlyBlacklister {
                                            blacklisted[_account] = true;
                                            emit Blacklisted(_account);
                                        }
                                    
                                        /**
                                         * @dev Removes account from blacklist
                                         * @param _account The address to remove from the blacklist
                                         */
                                        function unBlacklist(address _account) external onlyBlacklister {
                                            blacklisted[_account] = false;
                                            emit UnBlacklisted(_account);
                                        }
                                    
                                        function updateBlacklister(address _newBlacklister) external onlyOwner {
                                            require(
                                                _newBlacklister != address(0),
                                                "Blacklistable: new blacklister is the zero address"
                                            );
                                            blacklister = _newBlacklister;
                                            emit BlacklisterChanged(blacklister);
                                        }
                                    }
                                    
                                    // File: contracts/v1/FiatTokenV1.sol
                                    
                                    /**
                                     *
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @title FiatToken
                                     * @dev ERC20 Token backed by fiat reserves
                                     */
                                    contract FiatTokenV1 is AbstractFiatTokenV1, Ownable, Pausable, Blacklistable {
                                        using SafeMath for uint256;
                                    
                                        string public name;
                                        string public symbol;
                                        uint8 public decimals;
                                        string public currency;
                                        address public masterMinter;
                                        bool internal initialized;
                                    
                                        mapping(address => uint256) internal balances;
                                        mapping(address => mapping(address => uint256)) internal allowed;
                                        uint256 internal totalSupply_ = 0;
                                        mapping(address => bool) internal minters;
                                        mapping(address => uint256) internal minterAllowed;
                                    
                                        event Mint(address indexed minter, address indexed to, uint256 amount);
                                        event Burn(address indexed burner, uint256 amount);
                                        event MinterConfigured(address indexed minter, uint256 minterAllowedAmount);
                                        event MinterRemoved(address indexed oldMinter);
                                        event MasterMinterChanged(address indexed newMasterMinter);
                                    
                                        function initialize(
                                            string memory tokenName,
                                            string memory tokenSymbol,
                                            string memory tokenCurrency,
                                            uint8 tokenDecimals,
                                            address newMasterMinter,
                                            address newPauser,
                                            address newBlacklister,
                                            address newOwner
                                        ) public {
                                            require(!initialized, "FiatToken: contract is already initialized");
                                            require(
                                                newMasterMinter != address(0),
                                                "FiatToken: new masterMinter is the zero address"
                                            );
                                            require(
                                                newPauser != address(0),
                                                "FiatToken: new pauser is the zero address"
                                            );
                                            require(
                                                newBlacklister != address(0),
                                                "FiatToken: new blacklister is the zero address"
                                            );
                                            require(
                                                newOwner != address(0),
                                                "FiatToken: new owner is the zero address"
                                            );
                                    
                                            name = tokenName;
                                            symbol = tokenSymbol;
                                            currency = tokenCurrency;
                                            decimals = tokenDecimals;
                                            masterMinter = newMasterMinter;
                                            pauser = newPauser;
                                            blacklister = newBlacklister;
                                            setOwner(newOwner);
                                            initialized = true;
                                        }
                                    
                                        /**
                                         * @dev Throws if called by any account other than a minter
                                         */
                                        modifier onlyMinters() {
                                            require(minters[msg.sender], "FiatToken: caller is not a minter");
                                            _;
                                        }
                                    
                                        /**
                                         * @dev Function to mint tokens
                                         * @param _to The address that will receive the minted tokens.
                                         * @param _amount The amount of tokens to mint. Must be less than or equal
                                         * to the minterAllowance of the caller.
                                         * @return A boolean that indicates if the operation was successful.
                                         */
                                        function mint(address _to, uint256 _amount)
                                            external
                                            whenNotPaused
                                            onlyMinters
                                            notBlacklisted(msg.sender)
                                            notBlacklisted(_to)
                                            returns (bool)
                                        {
                                            require(_to != address(0), "FiatToken: mint to the zero address");
                                            require(_amount > 0, "FiatToken: mint amount not greater than 0");
                                    
                                            uint256 mintingAllowedAmount = minterAllowed[msg.sender];
                                            require(
                                                _amount <= mintingAllowedAmount,
                                                "FiatToken: mint amount exceeds minterAllowance"
                                            );
                                    
                                            totalSupply_ = totalSupply_.add(_amount);
                                            balances[_to] = balances[_to].add(_amount);
                                            minterAllowed[msg.sender] = mintingAllowedAmount.sub(_amount);
                                            emit Mint(msg.sender, _to, _amount);
                                            emit Transfer(address(0), _to, _amount);
                                            return true;
                                        }
                                    
                                        /**
                                         * @dev Throws if called by any account other than the masterMinter
                                         */
                                        modifier onlyMasterMinter() {
                                            require(
                                                msg.sender == masterMinter,
                                                "FiatToken: caller is not the masterMinter"
                                            );
                                            _;
                                        }
                                    
                                        /**
                                         * @dev Get minter allowance for an account
                                         * @param minter The address of the minter
                                         */
                                        function minterAllowance(address minter) external view returns (uint256) {
                                            return minterAllowed[minter];
                                        }
                                    
                                        /**
                                         * @dev Checks if account is a minter
                                         * @param account The address to check
                                         */
                                        function isMinter(address account) external view returns (bool) {
                                            return minters[account];
                                        }
                                    
                                        /**
                                         * @notice Amount of remaining tokens spender is allowed to transfer on
                                         * behalf of the token owner
                                         * @param owner     Token owner's address
                                         * @param spender   Spender's address
                                         * @return Allowance amount
                                         */
                                        function allowance(address owner, address spender)
                                            external
                                            override
                                            view
                                            returns (uint256)
                                        {
                                            return allowed[owner][spender];
                                        }
                                    
                                        /**
                                         * @dev Get totalSupply of token
                                         */
                                        function totalSupply() external override view returns (uint256) {
                                            return totalSupply_;
                                        }
                                    
                                        /**
                                         * @dev Get token balance of an account
                                         * @param account address The account
                                         */
                                        function balanceOf(address account)
                                            external
                                            override
                                            view
                                            returns (uint256)
                                        {
                                            return balances[account];
                                        }
                                    
                                        /**
                                         * @notice Set spender's allowance over the caller's tokens to be a given
                                         * value.
                                         * @param spender   Spender's address
                                         * @param value     Allowance amount
                                         * @return True if successful
                                         */
                                        function approve(address spender, uint256 value)
                                            external
                                            override
                                            whenNotPaused
                                            notBlacklisted(msg.sender)
                                            notBlacklisted(spender)
                                            returns (bool)
                                        {
                                            _approve(msg.sender, spender, value);
                                            return true;
                                        }
                                    
                                        /**
                                         * @dev Internal function to set allowance
                                         * @param owner     Token owner's address
                                         * @param spender   Spender's address
                                         * @param value     Allowance amount
                                         */
                                        function _approve(
                                            address owner,
                                            address spender,
                                            uint256 value
                                        ) internal override {
                                            require(owner != address(0), "ERC20: approve from the zero address");
                                            require(spender != address(0), "ERC20: approve to the zero address");
                                            allowed[owner][spender] = value;
                                            emit Approval(owner, spender, value);
                                        }
                                    
                                        /**
                                         * @notice Transfer tokens by spending allowance
                                         * @param from  Payer's address
                                         * @param to    Payee's address
                                         * @param value Transfer amount
                                         * @return True if successful
                                         */
                                        function transferFrom(
                                            address from,
                                            address to,
                                            uint256 value
                                        )
                                            external
                                            override
                                            whenNotPaused
                                            notBlacklisted(msg.sender)
                                            notBlacklisted(from)
                                            notBlacklisted(to)
                                            returns (bool)
                                        {
                                            require(
                                                value <= allowed[from][msg.sender],
                                                "ERC20: transfer amount exceeds allowance"
                                            );
                                            _transfer(from, to, value);
                                            allowed[from][msg.sender] = allowed[from][msg.sender].sub(value);
                                            return true;
                                        }
                                    
                                        /**
                                         * @notice Transfer tokens from the caller
                                         * @param to    Payee's address
                                         * @param value Transfer amount
                                         * @return True if successful
                                         */
                                        function transfer(address to, uint256 value)
                                            external
                                            override
                                            whenNotPaused
                                            notBlacklisted(msg.sender)
                                            notBlacklisted(to)
                                            returns (bool)
                                        {
                                            _transfer(msg.sender, to, value);
                                            return true;
                                        }
                                    
                                        /**
                                         * @notice Internal function to process transfers
                                         * @param from  Payer's address
                                         * @param to    Payee's address
                                         * @param value Transfer amount
                                         */
                                        function _transfer(
                                            address from,
                                            address to,
                                            uint256 value
                                        ) internal override {
                                            require(from != address(0), "ERC20: transfer from the zero address");
                                            require(to != address(0), "ERC20: transfer to the zero address");
                                            require(
                                                value <= balances[from],
                                                "ERC20: transfer amount exceeds balance"
                                            );
                                    
                                            balances[from] = balances[from].sub(value);
                                            balances[to] = balances[to].add(value);
                                            emit Transfer(from, to, value);
                                        }
                                    
                                        /**
                                         * @dev Function to add/update a new minter
                                         * @param minter The address of the minter
                                         * @param minterAllowedAmount The minting amount allowed for the minter
                                         * @return True if the operation was successful.
                                         */
                                        function configureMinter(address minter, uint256 minterAllowedAmount)
                                            external
                                            whenNotPaused
                                            onlyMasterMinter
                                            returns (bool)
                                        {
                                            minters[minter] = true;
                                            minterAllowed[minter] = minterAllowedAmount;
                                            emit MinterConfigured(minter, minterAllowedAmount);
                                            return true;
                                        }
                                    
                                        /**
                                         * @dev Function to remove a minter
                                         * @param minter The address of the minter to remove
                                         * @return True if the operation was successful.
                                         */
                                        function removeMinter(address minter)
                                            external
                                            onlyMasterMinter
                                            returns (bool)
                                        {
                                            minters[minter] = false;
                                            minterAllowed[minter] = 0;
                                            emit MinterRemoved(minter);
                                            return true;
                                        }
                                    
                                        /**
                                         * @dev allows a minter to burn some of its own tokens
                                         * Validates that caller is a minter and that sender is not blacklisted
                                         * amount is less than or equal to the minter's account balance
                                         * @param _amount uint256 the amount of tokens to be burned
                                         */
                                        function burn(uint256 _amount)
                                            external
                                            whenNotPaused
                                            onlyMinters
                                            notBlacklisted(msg.sender)
                                        {
                                            uint256 balance = balances[msg.sender];
                                            require(_amount > 0, "FiatToken: burn amount not greater than 0");
                                            require(balance >= _amount, "FiatToken: burn amount exceeds balance");
                                    
                                            totalSupply_ = totalSupply_.sub(_amount);
                                            balances[msg.sender] = balance.sub(_amount);
                                            emit Burn(msg.sender, _amount);
                                            emit Transfer(msg.sender, address(0), _amount);
                                        }
                                    
                                        function updateMasterMinter(address _newMasterMinter) external onlyOwner {
                                            require(
                                                _newMasterMinter != address(0),
                                                "FiatToken: new masterMinter is the zero address"
                                            );
                                            masterMinter = _newMasterMinter;
                                            emit MasterMinterChanged(masterMinter);
                                        }
                                    }
                                    
                                    // File: @openzeppelin/contracts/utils/Address.sol
                                    
                                    pragma solidity ^0.6.2;
                                    
                                    /**
                                     * @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) {
                                            // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
                                            // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
                                            // for accounts without code, i.e. `keccak256('')`
                                            bytes32 codehash;
                                    
                                                bytes32 accountHash
                                             = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
                                            // solhint-disable-next-line no-inline-assembly
                                            assembly {
                                                codehash := extcodehash(account)
                                            }
                                            return (codehash != accountHash && codehash != 0x0);
                                        }
                                    
                                        /**
                                         * @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"
                                            );
                                            return _functionCallWithValue(target, data, value, errorMessage);
                                        }
                                    
                                        function _functionCallWithValue(
                                            address target,
                                            bytes memory data,
                                            uint256 weiValue,
                                            string memory errorMessage
                                        ) private returns (bytes memory) {
                                            require(isContract(target), "Address: call to non-contract");
                                    
                                            // solhint-disable-next-line avoid-low-level-calls
                                            (bool success, bytes memory returndata) = target.call{
                                                value: weiValue
                                            }(data);
                                            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: @openzeppelin/contracts/token/ERC20/SafeERC20.sol
                                    
                                    pragma solidity ^0.6.0;
                                    
                                    /**
                                     * @title SafeERC20
                                     * @dev Wrappers around ERC20 operations that throw on failure (when the token
                                     * contract returns false). Tokens that return no value (and instead revert or
                                     * throw on failure) are also supported, non-reverting calls are assumed to be
                                     * successful.
                                     * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
                                     * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
                                     */
                                    library SafeERC20 {
                                        using SafeMath for uint256;
                                        using Address for address;
                                    
                                        function safeTransfer(
                                            IERC20 token,
                                            address to,
                                            uint256 value
                                        ) internal {
                                            _callOptionalReturn(
                                                token,
                                                abi.encodeWithSelector(token.transfer.selector, to, value)
                                            );
                                        }
                                    
                                        function safeTransferFrom(
                                            IERC20 token,
                                            address from,
                                            address to,
                                            uint256 value
                                        ) internal {
                                            _callOptionalReturn(
                                                token,
                                                abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
                                            );
                                        }
                                    
                                        /**
                                         * @dev Deprecated. This function has issues similar to the ones found in
                                         * {IERC20-approve}, and its usage is discouraged.
                                         *
                                         * Whenever possible, use {safeIncreaseAllowance} and
                                         * {safeDecreaseAllowance} instead.
                                         */
                                        function safeApprove(
                                            IERC20 token,
                                            address spender,
                                            uint256 value
                                        ) internal {
                                            // safeApprove should only be called when setting an initial allowance,
                                            // or when resetting it to zero. To increase and decrease it, use
                                            // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                                            // solhint-disable-next-line max-line-length
                                            require(
                                                (value == 0) || (token.allowance(address(this), spender) == 0),
                                                "SafeERC20: approve from non-zero to non-zero allowance"
                                            );
                                            _callOptionalReturn(
                                                token,
                                                abi.encodeWithSelector(token.approve.selector, spender, value)
                                            );
                                        }
                                    
                                        function safeIncreaseAllowance(
                                            IERC20 token,
                                            address spender,
                                            uint256 value
                                        ) internal {
                                            uint256 newAllowance = token.allowance(address(this), spender).add(
                                                value
                                            );
                                            _callOptionalReturn(
                                                token,
                                                abi.encodeWithSelector(
                                                    token.approve.selector,
                                                    spender,
                                                    newAllowance
                                                )
                                            );
                                        }
                                    
                                        function safeDecreaseAllowance(
                                            IERC20 token,
                                            address spender,
                                            uint256 value
                                        ) internal {
                                            uint256 newAllowance = token.allowance(address(this), spender).sub(
                                                value,
                                                "SafeERC20: decreased allowance below zero"
                                            );
                                            _callOptionalReturn(
                                                token,
                                                abi.encodeWithSelector(
                                                    token.approve.selector,
                                                    spender,
                                                    newAllowance
                                                )
                                            );
                                        }
                                    
                                        /**
                                         * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                                         * on the return value: the return value is optional (but if data is returned, it must not be false).
                                         * @param token The token targeted by the call.
                                         * @param data The call data (encoded using abi.encode or one of its variants).
                                         */
                                        function _callOptionalReturn(IERC20 token, bytes memory data) private {
                                            // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                                            // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                                            // the target address contains contract code and also asserts for success in the low-level call.
                                    
                                            bytes memory returndata = address(token).functionCall(
                                                data,
                                                "SafeERC20: low-level call failed"
                                            );
                                            if (returndata.length > 0) {
                                                // Return data is optional
                                                // solhint-disable-next-line max-line-length
                                                require(
                                                    abi.decode(returndata, (bool)),
                                                    "SafeERC20: ERC20 operation did not succeed"
                                                );
                                            }
                                        }
                                    }
                                    
                                    // File: contracts/v1.1/Rescuable.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    contract Rescuable is Ownable {
                                        using SafeERC20 for IERC20;
                                    
                                        address private _rescuer;
                                    
                                        event RescuerChanged(address indexed newRescuer);
                                    
                                        /**
                                         * @notice Returns current rescuer
                                         * @return Rescuer's address
                                         */
                                        function rescuer() external view returns (address) {
                                            return _rescuer;
                                        }
                                    
                                        /**
                                         * @notice Revert if called by any account other than the rescuer.
                                         */
                                        modifier onlyRescuer() {
                                            require(msg.sender == _rescuer, "Rescuable: caller is not the rescuer");
                                            _;
                                        }
                                    
                                        /**
                                         * @notice Rescue ERC20 tokens locked up in this contract.
                                         * @param tokenContract ERC20 token contract address
                                         * @param to        Recipient address
                                         * @param amount    Amount to withdraw
                                         */
                                        function rescueERC20(
                                            IERC20 tokenContract,
                                            address to,
                                            uint256 amount
                                        ) external onlyRescuer {
                                            tokenContract.safeTransfer(to, amount);
                                        }
                                    
                                        /**
                                         * @notice Assign the rescuer role to a given address.
                                         * @param newRescuer New rescuer's address
                                         */
                                        function updateRescuer(address newRescuer) external onlyOwner {
                                            require(
                                                newRescuer != address(0),
                                                "Rescuable: new rescuer is the zero address"
                                            );
                                            _rescuer = newRescuer;
                                            emit RescuerChanged(newRescuer);
                                        }
                                    }
                                    
                                    // File: contracts/v1.1/FiatTokenV1_1.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @title FiatTokenV1_1
                                     * @dev ERC20 Token backed by fiat reserves
                                     */
                                    contract FiatTokenV1_1 is FiatTokenV1, Rescuable {
                                    
                                    }
                                    
                                    // File: contracts/v2/AbstractFiatTokenV2.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    abstract contract AbstractFiatTokenV2 is AbstractFiatTokenV1 {
                                        function _increaseAllowance(
                                            address owner,
                                            address spender,
                                            uint256 increment
                                        ) internal virtual;
                                    
                                        function _decreaseAllowance(
                                            address owner,
                                            address spender,
                                            uint256 decrement
                                        ) internal virtual;
                                    }
                                    
                                    // File: contracts/util/ECRecover.sol
                                    
                                    /**
                                     * Copyright (c) 2016-2019 zOS Global Limited
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @title ECRecover
                                     * @notice A library that provides a safe ECDSA recovery function
                                     */
                                    library ECRecover {
                                        /**
                                         * @notice Recover signer's address from a signed message
                                         * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/65e4ffde586ec89af3b7e9140bdc9235d1254853/contracts/cryptography/ECDSA.sol
                                         * Modifications: Accept v, r, and s as separate arguments
                                         * @param digest    Keccak-256 hash digest of the signed message
                                         * @param v         v of the signature
                                         * @param r         r of the signature
                                         * @param s         s of the signature
                                         * @return Signer address
                                         */
                                        function recover(
                                            bytes32 digest,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) internal pure returns (address) {
                                            // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
                                            // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
                                            // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
                                            // signatures from current libraries generate a unique signature with an s-value in the lower half order.
                                            //
                                            // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
                                            // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
                                            // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
                                            // these malleable signatures as well.
                                            if (
                                                uint256(s) >
                                                0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0
                                            ) {
                                                revert("ECRecover: invalid signature 's' value");
                                            }
                                    
                                            if (v != 27 && v != 28) {
                                                revert("ECRecover: invalid signature 'v' value");
                                            }
                                    
                                            // If the signature is valid (and not malleable), return the signer address
                                            address signer = ecrecover(digest, v, r, s);
                                            require(signer != address(0), "ECRecover: invalid signature");
                                    
                                            return signer;
                                        }
                                    }
                                    
                                    // File: contracts/util/EIP712.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @title EIP712
                                     * @notice A library that provides EIP712 helper functions
                                     */
                                    library EIP712 {
                                        /**
                                         * @notice Make EIP712 domain separator
                                         * @param name      Contract name
                                         * @param version   Contract version
                                         * @return Domain separator
                                         */
                                        function makeDomainSeparator(string memory name, string memory version)
                                            internal
                                            view
                                            returns (bytes32)
                                        {
                                            uint256 chainId;
                                            assembly {
                                                chainId := chainid()
                                            }
                                            return
                                                keccak256(
                                                    abi.encode(
                                                        // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                                                        0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                                                        keccak256(bytes(name)),
                                                        keccak256(bytes(version)),
                                                        chainId,
                                                        address(this)
                                                    )
                                                );
                                        }
                                    
                                        /**
                                         * @notice Recover signer's address from a EIP712 signature
                                         * @param domainSeparator   Domain separator
                                         * @param v                 v of the signature
                                         * @param r                 r of the signature
                                         * @param s                 s of the signature
                                         * @param typeHashAndData   Type hash concatenated with data
                                         * @return Signer's address
                                         */
                                        function recover(
                                            bytes32 domainSeparator,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s,
                                            bytes memory typeHashAndData
                                        ) internal pure returns (address) {
                                            bytes32 digest = keccak256(
                                                abi.encodePacked(
                                                    "\x19\x01",
                                                    domainSeparator,
                                                    keccak256(typeHashAndData)
                                                )
                                            );
                                            return ECRecover.recover(digest, v, r, s);
                                        }
                                    }
                                    
                                    // File: contracts/v2/EIP712Domain.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @title EIP712 Domain
                                     */
                                    contract EIP712Domain {
                                        /**
                                         * @dev EIP712 Domain Separator
                                         */
                                        bytes32 public DOMAIN_SEPARATOR;
                                    }
                                    
                                    // File: contracts/v2/EIP3009.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @title EIP-3009
                                     * @notice Provide internal implementation for gas-abstracted transfers
                                     * @dev Contracts that inherit from this must wrap these with publicly
                                     * accessible functions, optionally adding modifiers where necessary
                                     */
                                    abstract contract EIP3009 is AbstractFiatTokenV2, EIP712Domain {
                                        // keccak256("TransferWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
                                        bytes32
                                            public constant TRANSFER_WITH_AUTHORIZATION_TYPEHASH = 0x7c7c6cdb67a18743f49ec6fa9b35f50d52ed05cbed4cc592e13b44501c1a2267;
                                    
                                        // keccak256("ReceiveWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
                                        bytes32
                                            public constant RECEIVE_WITH_AUTHORIZATION_TYPEHASH = 0xd099cc98ef71107a616c4f0f941f04c322d8e254fe26b3c6668db87aae413de8;
                                    
                                        // keccak256("CancelAuthorization(address authorizer,bytes32 nonce)")
                                        bytes32
                                            public constant CANCEL_AUTHORIZATION_TYPEHASH = 0x158b0a9edf7a828aad02f63cd515c68ef2f50ba807396f6d12842833a1597429;
                                    
                                        /**
                                         * @dev authorizer address => nonce => bool (true if nonce is used)
                                         */
                                        mapping(address => mapping(bytes32 => bool)) private _authorizationStates;
                                    
                                        event AuthorizationUsed(address indexed authorizer, bytes32 indexed nonce);
                                        event AuthorizationCanceled(
                                            address indexed authorizer,
                                            bytes32 indexed nonce
                                        );
                                    
                                        /**
                                         * @notice Returns the state of an authorization
                                         * @dev Nonces are randomly generated 32-byte data unique to the
                                         * authorizer's address
                                         * @param authorizer    Authorizer's address
                                         * @param nonce         Nonce of the authorization
                                         * @return True if the nonce is used
                                         */
                                        function authorizationState(address authorizer, bytes32 nonce)
                                            external
                                            view
                                            returns (bool)
                                        {
                                            return _authorizationStates[authorizer][nonce];
                                        }
                                    
                                        /**
                                         * @notice Execute a transfer with a signed authorization
                                         * @param from          Payer's address (Authorizer)
                                         * @param to            Payee's address
                                         * @param value         Amount to be transferred
                                         * @param validAfter    The time after which this is valid (unix time)
                                         * @param validBefore   The time before which this is valid (unix time)
                                         * @param nonce         Unique nonce
                                         * @param v             v of the signature
                                         * @param r             r of the signature
                                         * @param s             s of the signature
                                         */
                                        function _transferWithAuthorization(
                                            address from,
                                            address to,
                                            uint256 value,
                                            uint256 validAfter,
                                            uint256 validBefore,
                                            bytes32 nonce,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) internal {
                                            _requireValidAuthorization(from, nonce, validAfter, validBefore);
                                    
                                            bytes memory data = abi.encode(
                                                TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
                                                from,
                                                to,
                                                value,
                                                validAfter,
                                                validBefore,
                                                nonce
                                            );
                                            require(
                                                EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == from,
                                                "FiatTokenV2: invalid signature"
                                            );
                                    
                                            _markAuthorizationAsUsed(from, nonce);
                                            _transfer(from, to, value);
                                        }
                                    
                                        /**
                                         * @notice Receive a transfer with a signed authorization from the payer
                                         * @dev This has an additional check to ensure that the payee's address
                                         * matches the caller of this function to prevent front-running attacks.
                                         * @param from          Payer's address (Authorizer)
                                         * @param to            Payee's address
                                         * @param value         Amount to be transferred
                                         * @param validAfter    The time after which this is valid (unix time)
                                         * @param validBefore   The time before which this is valid (unix time)
                                         * @param nonce         Unique nonce
                                         * @param v             v of the signature
                                         * @param r             r of the signature
                                         * @param s             s of the signature
                                         */
                                        function _receiveWithAuthorization(
                                            address from,
                                            address to,
                                            uint256 value,
                                            uint256 validAfter,
                                            uint256 validBefore,
                                            bytes32 nonce,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) internal {
                                            require(to == msg.sender, "FiatTokenV2: caller must be the payee");
                                            _requireValidAuthorization(from, nonce, validAfter, validBefore);
                                    
                                            bytes memory data = abi.encode(
                                                RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
                                                from,
                                                to,
                                                value,
                                                validAfter,
                                                validBefore,
                                                nonce
                                            );
                                            require(
                                                EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == from,
                                                "FiatTokenV2: invalid signature"
                                            );
                                    
                                            _markAuthorizationAsUsed(from, nonce);
                                            _transfer(from, to, value);
                                        }
                                    
                                        /**
                                         * @notice Attempt to cancel an authorization
                                         * @param authorizer    Authorizer's address
                                         * @param nonce         Nonce of the authorization
                                         * @param v             v of the signature
                                         * @param r             r of the signature
                                         * @param s             s of the signature
                                         */
                                        function _cancelAuthorization(
                                            address authorizer,
                                            bytes32 nonce,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) internal {
                                            _requireUnusedAuthorization(authorizer, nonce);
                                    
                                            bytes memory data = abi.encode(
                                                CANCEL_AUTHORIZATION_TYPEHASH,
                                                authorizer,
                                                nonce
                                            );
                                            require(
                                                EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == authorizer,
                                                "FiatTokenV2: invalid signature"
                                            );
                                    
                                            _authorizationStates[authorizer][nonce] = true;
                                            emit AuthorizationCanceled(authorizer, nonce);
                                        }
                                    
                                        /**
                                         * @notice Check that an authorization is unused
                                         * @param authorizer    Authorizer's address
                                         * @param nonce         Nonce of the authorization
                                         */
                                        function _requireUnusedAuthorization(address authorizer, bytes32 nonce)
                                            private
                                            view
                                        {
                                            require(
                                                !_authorizationStates[authorizer][nonce],
                                                "FiatTokenV2: authorization is used or canceled"
                                            );
                                        }
                                    
                                        /**
                                         * @notice Check that authorization is valid
                                         * @param authorizer    Authorizer's address
                                         * @param nonce         Nonce of the authorization
                                         * @param validAfter    The time after which this is valid (unix time)
                                         * @param validBefore   The time before which this is valid (unix time)
                                         */
                                        function _requireValidAuthorization(
                                            address authorizer,
                                            bytes32 nonce,
                                            uint256 validAfter,
                                            uint256 validBefore
                                        ) private view {
                                            require(
                                                now > validAfter,
                                                "FiatTokenV2: authorization is not yet valid"
                                            );
                                            require(now < validBefore, "FiatTokenV2: authorization is expired");
                                            _requireUnusedAuthorization(authorizer, nonce);
                                        }
                                    
                                        /**
                                         * @notice Mark an authorization as used
                                         * @param authorizer    Authorizer's address
                                         * @param nonce         Nonce of the authorization
                                         */
                                        function _markAuthorizationAsUsed(address authorizer, bytes32 nonce)
                                            private
                                        {
                                            _authorizationStates[authorizer][nonce] = true;
                                            emit AuthorizationUsed(authorizer, nonce);
                                        }
                                    }
                                    
                                    // File: contracts/v2/EIP2612.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @title EIP-2612
                                     * @notice Provide internal implementation for gas-abstracted approvals
                                     */
                                    abstract contract EIP2612 is AbstractFiatTokenV2, EIP712Domain {
                                        // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
                                        bytes32
                                            public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
                                    
                                        mapping(address => uint256) private _permitNonces;
                                    
                                        /**
                                         * @notice Nonces for permit
                                         * @param owner Token owner's address (Authorizer)
                                         * @return Next nonce
                                         */
                                        function nonces(address owner) external view returns (uint256) {
                                            return _permitNonces[owner];
                                        }
                                    
                                        /**
                                         * @notice Verify a signed approval permit and execute if valid
                                         * @param owner     Token owner's address (Authorizer)
                                         * @param spender   Spender's address
                                         * @param value     Amount of allowance
                                         * @param deadline  The time at which this expires (unix time)
                                         * @param v         v of the signature
                                         * @param r         r of the signature
                                         * @param s         s of the signature
                                         */
                                        function _permit(
                                            address owner,
                                            address spender,
                                            uint256 value,
                                            uint256 deadline,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) internal {
                                            require(deadline >= now, "FiatTokenV2: permit is expired");
                                    
                                            bytes memory data = abi.encode(
                                                PERMIT_TYPEHASH,
                                                owner,
                                                spender,
                                                value,
                                                _permitNonces[owner]++,
                                                deadline
                                            );
                                            require(
                                                EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == owner,
                                                "EIP2612: invalid signature"
                                            );
                                    
                                            _approve(owner, spender, value);
                                        }
                                    }
                                    
                                    // File: contracts/v2/FiatTokenV2.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    /**
                                     * @title FiatToken V2
                                     * @notice ERC20 Token backed by fiat reserves, version 2
                                     */
                                    contract FiatTokenV2 is FiatTokenV1_1, EIP3009, EIP2612 {
                                        uint8 internal _initializedVersion;
                                    
                                        /**
                                         * @notice Initialize v2
                                         * @param newName   New token name
                                         */
                                        function initializeV2(string calldata newName) external {
                                            // solhint-disable-next-line reason-string
                                            require(initialized && _initializedVersion == 0);
                                            name = newName;
                                            DOMAIN_SEPARATOR = EIP712.makeDomainSeparator(newName, "2");
                                            _initializedVersion = 1;
                                        }
                                    
                                        /**
                                         * @notice Increase the allowance by a given increment
                                         * @param spender   Spender's address
                                         * @param increment Amount of increase in allowance
                                         * @return True if successful
                                         */
                                        function increaseAllowance(address spender, uint256 increment)
                                            external
                                            whenNotPaused
                                            notBlacklisted(msg.sender)
                                            notBlacklisted(spender)
                                            returns (bool)
                                        {
                                            _increaseAllowance(msg.sender, spender, increment);
                                            return true;
                                        }
                                    
                                        /**
                                         * @notice Decrease the allowance by a given decrement
                                         * @param spender   Spender's address
                                         * @param decrement Amount of decrease in allowance
                                         * @return True if successful
                                         */
                                        function decreaseAllowance(address spender, uint256 decrement)
                                            external
                                            whenNotPaused
                                            notBlacklisted(msg.sender)
                                            notBlacklisted(spender)
                                            returns (bool)
                                        {
                                            _decreaseAllowance(msg.sender, spender, decrement);
                                            return true;
                                        }
                                    
                                        /**
                                         * @notice Execute a transfer with a signed authorization
                                         * @param from          Payer's address (Authorizer)
                                         * @param to            Payee's address
                                         * @param value         Amount to be transferred
                                         * @param validAfter    The time after which this is valid (unix time)
                                         * @param validBefore   The time before which this is valid (unix time)
                                         * @param nonce         Unique nonce
                                         * @param v             v of the signature
                                         * @param r             r of the signature
                                         * @param s             s of the signature
                                         */
                                        function transferWithAuthorization(
                                            address from,
                                            address to,
                                            uint256 value,
                                            uint256 validAfter,
                                            uint256 validBefore,
                                            bytes32 nonce,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                                            _transferWithAuthorization(
                                                from,
                                                to,
                                                value,
                                                validAfter,
                                                validBefore,
                                                nonce,
                                                v,
                                                r,
                                                s
                                            );
                                        }
                                    
                                        /**
                                         * @notice Receive a transfer with a signed authorization from the payer
                                         * @dev This has an additional check to ensure that the payee's address
                                         * matches the caller of this function to prevent front-running attacks.
                                         * @param from          Payer's address (Authorizer)
                                         * @param to            Payee's address
                                         * @param value         Amount to be transferred
                                         * @param validAfter    The time after which this is valid (unix time)
                                         * @param validBefore   The time before which this is valid (unix time)
                                         * @param nonce         Unique nonce
                                         * @param v             v of the signature
                                         * @param r             r of the signature
                                         * @param s             s of the signature
                                         */
                                        function receiveWithAuthorization(
                                            address from,
                                            address to,
                                            uint256 value,
                                            uint256 validAfter,
                                            uint256 validBefore,
                                            bytes32 nonce,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                                            _receiveWithAuthorization(
                                                from,
                                                to,
                                                value,
                                                validAfter,
                                                validBefore,
                                                nonce,
                                                v,
                                                r,
                                                s
                                            );
                                        }
                                    
                                        /**
                                         * @notice Attempt to cancel an authorization
                                         * @dev Works only if the authorization is not yet used.
                                         * @param authorizer    Authorizer's address
                                         * @param nonce         Nonce of the authorization
                                         * @param v             v of the signature
                                         * @param r             r of the signature
                                         * @param s             s of the signature
                                         */
                                        function cancelAuthorization(
                                            address authorizer,
                                            bytes32 nonce,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) external whenNotPaused {
                                            _cancelAuthorization(authorizer, nonce, v, r, s);
                                        }
                                    
                                        /**
                                         * @notice Update allowance with a signed permit
                                         * @param owner       Token owner's address (Authorizer)
                                         * @param spender     Spender's address
                                         * @param value       Amount of allowance
                                         * @param deadline    Expiration time, seconds since the epoch
                                         * @param v           v of the signature
                                         * @param r           r of the signature
                                         * @param s           s of the signature
                                         */
                                        function permit(
                                            address owner,
                                            address spender,
                                            uint256 value,
                                            uint256 deadline,
                                            uint8 v,
                                            bytes32 r,
                                            bytes32 s
                                        ) external whenNotPaused notBlacklisted(owner) notBlacklisted(spender) {
                                            _permit(owner, spender, value, deadline, v, r, s);
                                        }
                                    
                                        /**
                                         * @notice Internal function to increase the allowance by a given increment
                                         * @param owner     Token owner's address
                                         * @param spender   Spender's address
                                         * @param increment Amount of increase
                                         */
                                        function _increaseAllowance(
                                            address owner,
                                            address spender,
                                            uint256 increment
                                        ) internal override {
                                            _approve(owner, spender, allowed[owner][spender].add(increment));
                                        }
                                    
                                        /**
                                         * @notice Internal function to decrease the allowance by a given decrement
                                         * @param owner     Token owner's address
                                         * @param spender   Spender's address
                                         * @param decrement Amount of decrease
                                         */
                                        function _decreaseAllowance(
                                            address owner,
                                            address spender,
                                            uint256 decrement
                                        ) internal override {
                                            _approve(
                                                owner,
                                                spender,
                                                allowed[owner][spender].sub(
                                                    decrement,
                                                    "ERC20: decreased allowance below zero"
                                                )
                                            );
                                        }
                                    }
                                    
                                    // File: contracts/v2/FiatTokenV2_1.sol
                                    
                                    /**
                                     * Copyright (c) 2018-2020 CENTRE SECZ
                                     *
                                     * Permission is hereby granted, free of charge, to any person obtaining a copy
                                     * of this software and associated documentation files (the "Software"), to deal
                                     * in the Software without restriction, including without limitation the rights
                                     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                                     * copies of the Software, and to permit persons to whom the Software is
                                     * furnished to do so, subject to the following conditions:
                                     *
                                     * The above copyright notice and this permission notice shall be included in
                                     * copies or substantial portions of the Software.
                                     *
                                     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                                     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                                     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                                     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                                     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                                     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                                     * SOFTWARE.
                                     */
                                    
                                    pragma solidity 0.6.12;
                                    
                                    // solhint-disable func-name-mixedcase
                                    
                                    /**
                                     * @title FiatToken V2.1
                                     * @notice ERC20 Token backed by fiat reserves, version 2.1
                                     */
                                    contract FiatTokenV2_1 is FiatTokenV2 {
                                        /**
                                         * @notice Initialize v2.1
                                         * @param lostAndFound  The address to which the locked funds are sent
                                         */
                                        function initializeV2_1(address lostAndFound) external {
                                            // solhint-disable-next-line reason-string
                                            require(_initializedVersion == 1);
                                    
                                            uint256 lockedAmount = balances[address(this)];
                                            if (lockedAmount > 0) {
                                                _transfer(address(this), lostAndFound, lockedAmount);
                                            }
                                            blacklisted[address(this)] = true;
                                    
                                            _initializedVersion = 2;
                                        }
                                    
                                        /**
                                         * @notice Version string for the EIP712 domain separator
                                         * @return Version string
                                         */
                                        function version() external view returns (string memory) {
                                            return "2";
                                        }
                                    }

                                    File 8 of 12: Endpoint
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity 0.7.6;
                                    import "./interfaces/ILayerZeroReceiver.sol";
                                    import "./interfaces/ILayerZeroEndpoint.sol";
                                    import "./interfaces/ILayerZeroMessagingLibrary.sol";
                                    import "@openzeppelin/contracts/access/Ownable.sol";
                                    contract Endpoint is Ownable, ILayerZeroEndpoint {
                                        uint16 public immutable chainId;
                                        // installed libraries and reserved versions
                                        uint16 public constant BLOCK_VERSION = 65535;
                                        uint16 public constant DEFAULT_VERSION = 0;
                                        uint16 public latestVersion;
                                        mapping(uint16 => ILayerZeroMessagingLibrary) public libraryLookup; // version -> ILayerZeroEndpointLibrary
                                        // default send/receive libraries
                                        uint16 public defaultSendVersion;
                                        uint16 public defaultReceiveVersion;
                                        ILayerZeroMessagingLibrary public defaultSendLibrary;
                                        address public defaultReceiveLibraryAddress;
                                        struct LibraryConfig {
                                            uint16 sendVersion;
                                            uint16 receiveVersion;
                                            address receiveLibraryAddress;
                                            ILayerZeroMessagingLibrary sendLibrary;
                                        }
                                        struct StoredPayload {
                                            uint64 payloadLength;
                                            address dstAddress;
                                            bytes32 payloadHash;
                                        }
                                        // user app config = [uaAddress]
                                        mapping(address => LibraryConfig) public uaConfigLookup;
                                        // inboundNonce = [srcChainId][srcAddress].
                                        mapping(uint16 => mapping(bytes => uint64)) public inboundNonce;
                                        // outboundNonce = [dstChainId][srcAddress].
                                        mapping(uint16 => mapping(address => uint64)) public outboundNonce;
                                        // storedPayload = [srcChainId][srcAddress]
                                        mapping(uint16 => mapping(bytes => StoredPayload)) public storedPayload;
                                        // library versioning events
                                        event NewLibraryVersionAdded(uint16 version);
                                        event DefaultSendVersionSet(uint16 version);
                                        event DefaultReceiveVersionSet(uint16 version);
                                        event UaSendVersionSet(address ua, uint16 version);
                                        event UaReceiveVersionSet(address ua, uint16 version);
                                        event UaForceResumeReceive(uint16 chainId, bytes srcAddress);
                                        // payload events
                                        event PayloadCleared(uint16 srcChainId, bytes srcAddress, uint64 nonce, address dstAddress);
                                        event PayloadStored(uint16 srcChainId, bytes srcAddress, address dstAddress, uint64 nonce, bytes payload, bytes reason);
                                        constructor(uint16 _chainId) {
                                            chainId = _chainId;
                                        }
                                        //---------------------------------------------------------------------------
                                        // send and receive nonreentrant lock
                                        uint8 internal constant _NOT_ENTERED = 1;
                                        uint8 internal constant _ENTERED = 2;
                                        uint8 internal _send_entered_state = 1;
                                        uint8 internal _receive_entered_state = 1;
                                        modifier sendNonReentrant() {
                                            require(_send_entered_state == _NOT_ENTERED, "LayerZero: no send reentrancy");
                                            _send_entered_state = _ENTERED;
                                            _;
                                            _send_entered_state = _NOT_ENTERED;
                                        }
                                        modifier receiveNonReentrant() {
                                            require(_receive_entered_state == _NOT_ENTERED, "LayerZero: no receive reentrancy");
                                            _receive_entered_state = _ENTERED;
                                            _;
                                            _receive_entered_state = _NOT_ENTERED;
                                        }
                                        // BLOCK_VERSION is also a valid version
                                        modifier validVersion(uint16 _version) {
                                            require(_version <= latestVersion || _version == BLOCK_VERSION, "LayerZero: invalid messaging library version");
                                            _;
                                        }
                                        //---------------------------------------------------------------------------
                                        // User Application Calls - Endpoint Interface
                                        function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable override sendNonReentrant {
                                            LibraryConfig storage uaConfig = uaConfigLookup[msg.sender];
                                            uint64 nonce = ++outboundNonce[_dstChainId][msg.sender];
                                            _getSendLibrary(uaConfig).send{value: msg.value}(msg.sender, nonce, _dstChainId, _destination, _payload, _refundAddress, _zroPaymentAddress, _adapterParams);
                                        }
                                        //---------------------------------------------------------------------------
                                        // authenticated Library (msg.sender) Calls to pass through Endpoint to UA (dstAddress)
                                        function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _payload) external override receiveNonReentrant {
                                            // assert and increment the nonce. no message shuffling
                                            require(_nonce == ++inboundNonce[_srcChainId][_srcAddress], "LayerZero: wrong nonce");
                                            LibraryConfig storage uaConfig = uaConfigLookup[_dstAddress];
                                            // authentication to prevent cross-version message validation
                                            // protects against a malicious library from passing arbitrary data
                                            if (uaConfig.receiveVersion == DEFAULT_VERSION) {
                                                require(defaultReceiveLibraryAddress == msg.sender, "LayerZero: invalid default library");
                                            } else {
                                                require(uaConfig.receiveLibraryAddress == msg.sender, "LayerZero: invalid library");
                                            }
                                            // block if any message blocking
                                            StoredPayload storage sp = storedPayload[_srcChainId][_srcAddress];
                                            require(sp.payloadHash == bytes32(0), "LayerZero: in message blocking");
                                            try ILayerZeroReceiver(_dstAddress).lzReceive{gas: _gasLimit}(_srcChainId, _srcAddress, _nonce, _payload) {
                                                // success, do nothing, end of the message delivery
                                            } catch (bytes memory reason) {
                                                // revert nonce if any uncaught errors/exceptions if the ua chooses the blocking mode
                                                storedPayload[_srcChainId][_srcAddress] = StoredPayload(uint64(_payload.length), _dstAddress, keccak256(_payload));
                                                emit PayloadStored(_srcChainId, _srcAddress, _dstAddress, _nonce, _payload, reason);
                                            }
                                        }
                                        function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _payload) external override receiveNonReentrant {
                                            StoredPayload storage sp = storedPayload[_srcChainId][_srcAddress];
                                            require(sp.payloadHash != bytes32(0), "LayerZero: no stored payload");
                                            require(_payload.length == sp.payloadLength && keccak256(_payload) == sp.payloadHash, "LayerZero: invalid payload");
                                            address dstAddress = sp.dstAddress;
                                            // empty the storedPayload
                                            sp.payloadLength = 0;
                                            sp.dstAddress = address(0);
                                            sp.payloadHash = bytes32(0);
                                            uint64 nonce = inboundNonce[_srcChainId][_srcAddress];
                                            ILayerZeroReceiver(dstAddress).lzReceive(_srcChainId, _srcAddress, nonce, _payload);
                                            emit PayloadCleared(_srcChainId, _srcAddress, nonce, dstAddress);
                                        }
                                        //---------------------------------------------------------------------------
                                        // Owner Calls, only new library version upgrade (3 steps)
                                        // note libraryLookup[0] = 0x0, no library implementation
                                        // LIBRARY UPGRADE step 1: set _newLayerZeroLibraryAddress be the new version
                                        function newVersion(address _newLayerZeroLibraryAddress) external onlyOwner {
                                            require(_newLayerZeroLibraryAddress != address(0x0), "LayerZero: new version cannot be zero address");
                                            require(latestVersion < 65535, "LayerZero: can not add new messaging library");
                                            latestVersion++;
                                            libraryLookup[latestVersion] = ILayerZeroMessagingLibrary(_newLayerZeroLibraryAddress);
                                            emit NewLibraryVersionAdded(latestVersion);
                                        }
                                        // LIBRARY UPGRADE step 2: stop sending messages from the old version
                                        function setDefaultSendVersion(uint16 _newDefaultSendVersion) external onlyOwner validVersion(_newDefaultSendVersion) {
                                            require(_newDefaultSendVersion != DEFAULT_VERSION, "LayerZero: default send version must > 0");
                                            defaultSendVersion = _newDefaultSendVersion;
                                            defaultSendLibrary = libraryLookup[defaultSendVersion];
                                            emit DefaultSendVersionSet(_newDefaultSendVersion);
                                        }
                                        // LIBRARY UPGRADE step 3: stop receiving messages from the old version
                                        function setDefaultReceiveVersion(uint16 _newDefaultReceiveVersion) external onlyOwner validVersion(_newDefaultReceiveVersion) {
                                            require(_newDefaultReceiveVersion != DEFAULT_VERSION, "LayerZero: default receive version must > 0");
                                            defaultReceiveVersion = _newDefaultReceiveVersion;
                                            defaultReceiveLibraryAddress = address(libraryLookup[defaultReceiveVersion]);
                                            emit DefaultReceiveVersionSet(_newDefaultReceiveVersion);
                                        }
                                        //---------------------------------------------------------------------------
                                        // User Application Calls - UA set/get Interface
                                        function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external override validVersion(_version) {
                                            if (_version == DEFAULT_VERSION) {
                                                require(defaultSendVersion == defaultReceiveVersion, "LayerZero: can not set Config during DEFAULT migration");
                                                _version = defaultSendVersion;
                                            }
                                            require(_version != BLOCK_VERSION, "LayerZero: can not set config for BLOCK_VERSION");
                                            libraryLookup[_version].setConfig(_chainId, msg.sender, _configType, _config);
                                        }
                                        // Migration step 1: set the send version
                                        // Define what library the UA points too
                                        function setSendVersion(uint16 _newVersion) external override validVersion(_newVersion) {
                                            // write into config
                                            LibraryConfig storage uaConfig = uaConfigLookup[msg.sender];
                                            uaConfig.sendVersion = _newVersion;
                                            // the libraryLookup[BLOCK_VERSION || DEFAULT_VERSION] = 0x0
                                            uaConfig.sendLibrary = libraryLookup[_newVersion];
                                            emit UaSendVersionSet(msg.sender, _newVersion);
                                        }
                                        // Migration step 2: set the receive version
                                        // after all messages sent from the old version are received
                                        // the UA can now safely switch to the new receive version
                                        // it is the UA's responsibility make sure all messages from the old version are processed
                                        function setReceiveVersion(uint16 _newVersion) external override validVersion(_newVersion) {
                                            // write into config
                                            LibraryConfig storage uaConfig = uaConfigLookup[msg.sender];
                                            uaConfig.receiveVersion = _newVersion;
                                            // the libraryLookup[BLOCK_VERSION || DEFAULT_VERSION] = 0x0
                                            uaConfig.receiveLibraryAddress = address(libraryLookup[_newVersion]);
                                            emit UaReceiveVersionSet(msg.sender, _newVersion);
                                        }
                                        function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external override {
                                            StoredPayload storage sp = storedPayload[_srcChainId][_srcAddress];
                                            // revert if no messages are cached. safeguard malicious UA behaviour
                                            require(sp.payloadHash != bytes32(0), "LayerZero: no stored payload");
                                            require(sp.dstAddress == msg.sender, "LayerZero: invalid caller");
                                            // empty the storedPayload
                                            sp.payloadLength = 0;
                                            sp.dstAddress = address(0);
                                            sp.payloadHash = bytes32(0);
                                            // emit the event with the new nonce
                                            emit UaForceResumeReceive(_srcChainId, _srcAddress);
                                        }
                                        //---------------------------------------------------------------------------
                                        // view helper function
                                        function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParams) external view override returns (uint nativeFee, uint zroFee) {
                                            LibraryConfig storage uaConfig = uaConfigLookup[_userApplication];
                                            ILayerZeroMessagingLibrary lib = uaConfig.sendVersion == DEFAULT_VERSION ? defaultSendLibrary : uaConfig.sendLibrary;
                                            return lib.estimateFees(_dstChainId, _userApplication, _payload, _payInZRO, _adapterParams);
                                        }
                                        function _getSendLibrary(LibraryConfig storage uaConfig) internal view returns (ILayerZeroMessagingLibrary) {
                                            if (uaConfig.sendVersion == DEFAULT_VERSION) {
                                                // check if the in send-blocking upgrade
                                                require(defaultSendVersion != BLOCK_VERSION, "LayerZero: default in BLOCK_VERSION");
                                                return defaultSendLibrary;
                                            } else {
                                                // check if the in send-blocking upgrade
                                                require(uaConfig.sendVersion != BLOCK_VERSION, "LayerZero: in BLOCK_VERSION");
                                                return uaConfig.sendLibrary;
                                            }
                                        }
                                        function getSendLibraryAddress(address _userApplication) external view override returns (address sendLibraryAddress) {
                                            LibraryConfig storage uaConfig = uaConfigLookup[_userApplication];
                                            uint16 sendVersion = uaConfig.sendVersion;
                                            require(sendVersion != BLOCK_VERSION, "LayerZero: send version is BLOCK_VERSION");
                                            if (sendVersion == DEFAULT_VERSION) {
                                                require(defaultSendVersion != BLOCK_VERSION, "LayerZero: send version (default) is BLOCK_VERSION");
                                                sendLibraryAddress = address(defaultSendLibrary);
                                            } else {
                                                sendLibraryAddress = address(uaConfig.sendLibrary);
                                            }
                                        }
                                        function getReceiveLibraryAddress(address _userApplication) external view override returns (address receiveLibraryAddress) {
                                            LibraryConfig storage uaConfig = uaConfigLookup[_userApplication];
                                            uint16 receiveVersion = uaConfig.receiveVersion;
                                            require(receiveVersion != BLOCK_VERSION, "LayerZero: receive version is BLOCK_VERSION");
                                            if (receiveVersion == DEFAULT_VERSION) {
                                                require(defaultReceiveVersion != BLOCK_VERSION, "LayerZero: receive version (default) is BLOCK_VERSION");
                                                receiveLibraryAddress = defaultReceiveLibraryAddress;
                                            } else {
                                                receiveLibraryAddress = uaConfig.receiveLibraryAddress;
                                            }
                                        }
                                        function isSendingPayload() external view override returns (bool) {
                                            return _send_entered_state == _ENTERED;
                                        }
                                        function isReceivingPayload() external view override returns (bool) {
                                            return _receive_entered_state == _ENTERED;
                                        }
                                        function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view override returns (uint64) {
                                            return inboundNonce[_srcChainId][_srcAddress];
                                        }
                                        function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view override returns (uint64) {
                                            return outboundNonce[_dstChainId][_srcAddress];
                                        }
                                        function getChainId() external view override returns (uint16) {
                                            return chainId;
                                        }
                                        function getSendVersion(address _userApplication) external view override returns (uint16) {
                                            LibraryConfig storage uaConfig = uaConfigLookup[_userApplication];
                                            return uaConfig.sendVersion == DEFAULT_VERSION ? defaultSendVersion : uaConfig.sendVersion;
                                        }
                                        function getReceiveVersion(address _userApplication) external view override returns (uint16) {
                                            LibraryConfig storage uaConfig = uaConfigLookup[_userApplication];
                                            return uaConfig.receiveVersion == DEFAULT_VERSION ? defaultReceiveVersion : uaConfig.receiveVersion;
                                        }
                                        function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view override validVersion(_version) returns (bytes memory) {
                                            if (_version == DEFAULT_VERSION) {
                                                require(defaultSendVersion == defaultReceiveVersion, "LayerZero: no DEFAULT config while migration");
                                                _version = defaultSendVersion;
                                            }
                                            require(_version != BLOCK_VERSION, "LayerZero: can not get config for BLOCK_VERSION");
                                            return libraryLookup[_version].getConfig(_chainId, _userApplication, _configType);
                                        }
                                        function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view override returns (bool) {
                                            StoredPayload storage sp = storedPayload[_srcChainId][_srcAddress];
                                            return sp.payloadHash != bytes32(0);
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.5.0;
                                    interface ILayerZeroReceiver {
                                        // @notice LayerZero endpoint will invoke this function to deliver the message on the destination
                                        // @param _srcChainId - the source endpoint identifier
                                        // @param _srcAddress - the source sending contract address from the source chain
                                        // @param _nonce - the ordered message nonce
                                        // @param _payload - the signed payload is the UA bytes has encoded to be sent
                                        function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) external;
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.5.0;
                                    import "./ILayerZeroUserApplicationConfig.sol";
                                    interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
                                        // @notice send a LayerZero message to the specified address at a LayerZero endpoint.
                                        // @param _dstChainId - the destination chain identifier
                                        // @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
                                        // @param _payload - a custom bytes payload to send to the destination contract
                                        // @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
                                        // @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
                                        // @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
                                        function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
                                        // @notice used by the messaging library to publish verified payload
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source contract (as bytes) at the source chain
                                        // @param _dstAddress - the address on destination chain
                                        // @param _nonce - the unbound message ordering nonce
                                        // @param _gasLimit - the gas limit for external contract execution
                                        // @param _payload - verified payload to send to the destination contract
                                        function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _payload) external;
                                        // @notice get the inboundNonce of a receiver from a source chain which could be EVM or non-EVM chain
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source chain contract address
                                        function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (uint64);
                                        // @notice get the outboundNonce from this source chain which, consequently, is always an EVM
                                        // @param _srcAddress - the source chain contract address
                                        function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view returns (uint64);
                                        // @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
                                        // @param _dstChainId - the destination chain identifier
                                        // @param _userApplication - the user app address on this EVM chain
                                        // @param _payload - the custom message to send over LayerZero
                                        // @param _payInZRO - if false, user app pays the protocol fee in native token
                                        // @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
                                        function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);
                                        // @notice get this Endpoint's immutable source identifier
                                        function getChainId() external view returns (uint16);
                                        // @notice the interface to retry failed message on this Endpoint destination
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source chain contract address
                                        // @param _payload - the payload to be retried
                                        function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _payload) external;
                                        // @notice query if any STORED payload (message blocking) at the endpoint.
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source chain contract address
                                        function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool);
                                        // @notice query if the _libraryAddress is valid for sending msgs.
                                        // @param _userApplication - the user app address on this EVM chain
                                        function getSendLibraryAddress(address _userApplication) external view returns (address);
                                        // @notice query if the _libraryAddress is valid for receiving msgs.
                                        // @param _userApplication - the user app address on this EVM chain
                                        function getReceiveLibraryAddress(address _userApplication) external view returns (address);
                                        // @notice query if the non-reentrancy guard for send() is on
                                        // @return true if the guard is on. false otherwise
                                        function isSendingPayload() external view returns (bool);
                                        // @notice query if the non-reentrancy guard for receive() is on
                                        // @return true if the guard is on. false otherwise
                                        function isReceivingPayload() external view returns (bool);
                                        // @notice get the configuration of the LayerZero messaging library of the specified version
                                        // @param _version - messaging library version
                                        // @param _chainId - the chainId for the pending config change
                                        // @param _userApplication - the contract address of the user application
                                        // @param _configType - type of configuration. every messaging library has its own convention.
                                        function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);
                                        // @notice get the send() LayerZero messaging library version
                                        // @param _userApplication - the contract address of the user application
                                        function getSendVersion(address _userApplication) external view returns (uint16);
                                        // @notice get the lzReceive() LayerZero messaging library version
                                        // @param _userApplication - the contract address of the user application
                                        function getReceiveVersion(address _userApplication) external view returns (uint16);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.7.0;
                                    import "./ILayerZeroUserApplicationConfig.sol";
                                    interface ILayerZeroMessagingLibrary {
                                        // send(), messages will be inflight.
                                        function send(address _userApplication, uint64 _lastNonce, uint16 _chainId, bytes calldata _destination, bytes calldata _payload, address payable refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
                                        // estimate native fee at the send side
                                        function estimateFees(uint16 _chainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);
                                        //---------------------------------------------------------------------------
                                        // setConfig / getConfig are User Application (UA) functions to specify Oracle, Relayer, blockConfirmations, libraryVersion
                                        function setConfig(uint16 _chainId, address _userApplication, uint _configType, bytes calldata _config) external;
                                        function getConfig(uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.7.0;
                                    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: BUSL-1.1
                                    pragma solidity >=0.5.0;
                                    interface ILayerZeroUserApplicationConfig {
                                        // @notice set the configuration of the LayerZero messaging library of the specified version
                                        // @param _version - messaging library version
                                        // @param _chainId - the chainId for the pending config change
                                        // @param _configType - type of configuration. every messaging library has its own convention.
                                        // @param _config - configuration in the bytes. can encode arbitrary content.
                                        function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external;
                                        // @notice set the send() LayerZero messaging library version to _version
                                        // @param _version - new messaging library version
                                        function setSendVersion(uint16 _version) external;
                                        // @notice set the lzReceive() LayerZero messaging library version to _version
                                        // @param _version - new messaging library version
                                        function setReceiveVersion(uint16 _version) external;
                                        // @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
                                        // @param _srcChainId - the chainId of the source chain
                                        // @param _srcAddress - the contract address of the source contract at the source chain
                                        function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external;
                                    }
                                    // 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;
                                        }
                                    }
                                    

                                    File 9 of 12: NonceContract
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity 0.7.6;
                                    import "./interfaces/ILayerZeroEndpoint.sol";
                                    contract NonceContract {
                                        ILayerZeroEndpoint public immutable endpoint;
                                        // outboundNonce = [dstChainId][remoteAddress + localAddress]
                                        mapping(uint16 => mapping(bytes => uint64)) public outboundNonce;
                                        constructor(address _endpoint) {
                                            endpoint = ILayerZeroEndpoint(_endpoint);
                                        }
                                        function increment(uint16 _chainId, address _ua, bytes calldata _path) external returns (uint64) {
                                            require(endpoint.getSendLibraryAddress(_ua) == msg.sender, "NonceContract: msg.sender is not valid sendlibrary");
                                            return ++outboundNonce[_chainId][_path];
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.5.0;
                                    import "./ILayerZeroUserApplicationConfig.sol";
                                    interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
                                        // @notice send a LayerZero message to the specified address at a LayerZero endpoint.
                                        // @param _dstChainId - the destination chain identifier
                                        // @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
                                        // @param _payload - a custom bytes payload to send to the destination contract
                                        // @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
                                        // @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
                                        // @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
                                        function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
                                        // @notice used by the messaging library to publish verified payload
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source contract (as bytes) at the source chain
                                        // @param _dstAddress - the address on destination chain
                                        // @param _nonce - the unbound message ordering nonce
                                        // @param _gasLimit - the gas limit for external contract execution
                                        // @param _payload - verified payload to send to the destination contract
                                        function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _payload) external;
                                        // @notice get the inboundNonce of a receiver from a source chain which could be EVM or non-EVM chain
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source chain contract address
                                        function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (uint64);
                                        // @notice get the outboundNonce from this source chain which, consequently, is always an EVM
                                        // @param _srcAddress - the source chain contract address
                                        function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view returns (uint64);
                                        // @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
                                        // @param _dstChainId - the destination chain identifier
                                        // @param _userApplication - the user app address on this EVM chain
                                        // @param _payload - the custom message to send over LayerZero
                                        // @param _payInZRO - if false, user app pays the protocol fee in native token
                                        // @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
                                        function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);
                                        // @notice get this Endpoint's immutable source identifier
                                        function getChainId() external view returns (uint16);
                                        // @notice the interface to retry failed message on this Endpoint destination
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source chain contract address
                                        // @param _payload - the payload to be retried
                                        function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _payload) external;
                                        // @notice query if any STORED payload (message blocking) at the endpoint.
                                        // @param _srcChainId - the source chain identifier
                                        // @param _srcAddress - the source chain contract address
                                        function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool);
                                        // @notice query if the _libraryAddress is valid for sending msgs.
                                        // @param _userApplication - the user app address on this EVM chain
                                        function getSendLibraryAddress(address _userApplication) external view returns (address);
                                        // @notice query if the _libraryAddress is valid for receiving msgs.
                                        // @param _userApplication - the user app address on this EVM chain
                                        function getReceiveLibraryAddress(address _userApplication) external view returns (address);
                                        // @notice query if the non-reentrancy guard for send() is on
                                        // @return true if the guard is on. false otherwise
                                        function isSendingPayload() external view returns (bool);
                                        // @notice query if the non-reentrancy guard for receive() is on
                                        // @return true if the guard is on. false otherwise
                                        function isReceivingPayload() external view returns (bool);
                                        // @notice get the configuration of the LayerZero messaging library of the specified version
                                        // @param _version - messaging library version
                                        // @param _chainId - the chainId for the pending config change
                                        // @param _userApplication - the contract address of the user application
                                        // @param _configType - type of configuration. every messaging library has its own convention.
                                        function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);
                                        // @notice get the send() LayerZero messaging library version
                                        // @param _userApplication - the contract address of the user application
                                        function getSendVersion(address _userApplication) external view returns (uint16);
                                        // @notice get the lzReceive() LayerZero messaging library version
                                        // @param _userApplication - the contract address of the user application
                                        function getReceiveVersion(address _userApplication) external view returns (uint16);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.5.0;
                                    interface ILayerZeroUserApplicationConfig {
                                        // @notice set the configuration of the LayerZero messaging library of the specified version
                                        // @param _version - messaging library version
                                        // @param _chainId - the chainId for the pending config change
                                        // @param _configType - type of configuration. every messaging library has its own convention.
                                        // @param _config - configuration in the bytes. can encode arbitrary content.
                                        function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external;
                                        // @notice set the send() LayerZero messaging library version to _version
                                        // @param _version - new messaging library version
                                        function setSendVersion(uint16 _version) external;
                                        // @notice set the lzReceive() LayerZero messaging library version to _version
                                        // @param _version - new messaging library version
                                        function setReceiveVersion(uint16 _version) external;
                                        // @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
                                        // @param _srcChainId - the chainId of the source chain
                                        // @param _srcAddress - the contract address of the source contract at the source chain
                                        function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external;
                                    }
                                    

                                    File 10 of 12: OptimizedTransparentUpgradeableProxy
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.5.0-rc.0) (interfaces/draft-IERC1822.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
                                     * proxy whose upgrades are fully controlled by the current implementation.
                                     */
                                    interface IERC1822Proxiable {
                                        /**
                                         * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
                                         * address.
                                         *
                                         * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
                                         * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
                                         * function revert if invoked through a proxy.
                                         */
                                        function proxiableUUID() external view returns (bytes32);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (proxy/ERC1967/ERC1967Proxy.sol)
                                    pragma solidity ^0.8.0;
                                    import "../Proxy.sol";
                                    import "./ERC1967Upgrade.sol";
                                    /**
                                     * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
                                     * implementation address that can be changed. This address is stored in storage in the location specified by
                                     * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
                                     * implementation behind the proxy.
                                     */
                                    contract ERC1967Proxy is Proxy, ERC1967Upgrade {
                                        /**
                                         * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                                         *
                                         * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                                         * function call, and allows initializating the storage of the proxy like a Solidity constructor.
                                         */
                                        constructor(address _logic, bytes memory _data) payable {
                                            assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                                            _upgradeToAndCall(_logic, _data, false);
                                        }
                                        /**
                                         * @dev Returns the current implementation address.
                                         */
                                        function _implementation() internal view virtual override returns (address impl) {
                                            return ERC1967Upgrade._getImplementation();
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.5.0-rc.0) (proxy/ERC1967/ERC1967Upgrade.sol)
                                    pragma solidity ^0.8.2;
                                    import "../beacon/IBeacon.sol";
                                    import "../../interfaces/draft-IERC1822.sol";
                                    import "../../utils/Address.sol";
                                    import "../../utils/StorageSlot.sol";
                                    /**
                                     * @dev This abstract contract provides getters and event emitting update functions for
                                     * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
                                     *
                                     * _Available since v4.1._
                                     *
                                     * @custom:oz-upgrades-unsafe-allow delegatecall
                                     */
                                    abstract contract ERC1967Upgrade {
                                        // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
                                        bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
                                        /**
                                         * @dev Storage slot with the address of the current implementation.
                                         * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                                         * validated in the constructor.
                                         */
                                        bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                        /**
                                         * @dev Emitted when the implementation is upgraded.
                                         */
                                        event Upgraded(address indexed implementation);
                                        /**
                                         * @dev Returns the current implementation address.
                                         */
                                        function _getImplementation() internal view returns (address) {
                                            return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                        }
                                        /**
                                         * @dev Stores a new address in the EIP1967 implementation slot.
                                         */
                                        function _setImplementation(address newImplementation) private {
                                            require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                            StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                        }
                                        /**
                                         * @dev Perform implementation upgrade
                                         *
                                         * Emits an {Upgraded} event.
                                         */
                                        function _upgradeTo(address newImplementation) internal {
                                            _setImplementation(newImplementation);
                                            emit Upgraded(newImplementation);
                                        }
                                        /**
                                         * @dev Perform implementation upgrade with additional setup call.
                                         *
                                         * Emits an {Upgraded} event.
                                         */
                                        function _upgradeToAndCall(
                                            address newImplementation,
                                            bytes memory data,
                                            bool forceCall
                                        ) internal {
                                            _upgradeTo(newImplementation);
                                            if (data.length > 0 || forceCall) {
                                                Address.functionDelegateCall(newImplementation, data);
                                            }
                                        }
                                        /**
                                         * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
                                         *
                                         * Emits an {Upgraded} event.
                                         */
                                        function _upgradeToAndCallUUPS(
                                            address newImplementation,
                                            bytes memory data,
                                            bool forceCall
                                        ) internal {
                                            // Upgrades from old implementations will perform a rollback test. This test requires the new
                                            // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
                                            // this special case will break upgrade paths from old UUPS implementation to new ones.
                                            if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
                                                _setImplementation(newImplementation);
                                            } else {
                                                try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                                                    require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
                                                } catch {
                                                    revert("ERC1967Upgrade: new implementation is not UUPS");
                                                }
                                                _upgradeToAndCall(newImplementation, data, forceCall);
                                            }
                                        }
                                        /**
                                         * @dev Storage slot with the admin of the contract.
                                         * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                                         * validated in the constructor.
                                         */
                                        bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                                        /**
                                         * @dev Emitted when the admin account has changed.
                                         */
                                        event AdminChanged(address previousAdmin, address newAdmin);
                                        /**
                                         * @dev Returns the current admin.
                                         */
                                        function _getAdmin() internal view virtual returns (address) {
                                            return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
                                        }
                                        /**
                                         * @dev Stores a new address in the EIP1967 admin slot.
                                         */
                                        function _setAdmin(address newAdmin) private {
                                            require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                                            StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
                                        }
                                        /**
                                         * @dev Changes the admin of the proxy.
                                         *
                                         * Emits an {AdminChanged} event.
                                         */
                                        function _changeAdmin(address newAdmin) internal {
                                            emit AdminChanged(_getAdmin(), newAdmin);
                                            _setAdmin(newAdmin);
                                        }
                                        /**
                                         * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
                                         * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
                                         */
                                        bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
                                        /**
                                         * @dev Emitted when the beacon is upgraded.
                                         */
                                        event BeaconUpgraded(address indexed beacon);
                                        /**
                                         * @dev Returns the current beacon.
                                         */
                                        function _getBeacon() internal view returns (address) {
                                            return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
                                        }
                                        /**
                                         * @dev Stores a new beacon in the EIP1967 beacon slot.
                                         */
                                        function _setBeacon(address newBeacon) private {
                                            require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
                                            require(Address.isContract(IBeacon(newBeacon).implementation()), "ERC1967: beacon implementation is not a contract");
                                            StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
                                        }
                                        /**
                                         * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
                                         * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
                                         *
                                         * Emits a {BeaconUpgraded} event.
                                         */
                                        function _upgradeBeaconToAndCall(
                                            address newBeacon,
                                            bytes memory data,
                                            bool forceCall
                                        ) internal {
                                            _setBeacon(newBeacon);
                                            emit BeaconUpgraded(newBeacon);
                                            if (data.length > 0 || forceCall) {
                                                Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.5.0-rc.0) (proxy/Proxy.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                                     * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                                     * be specified by overriding the virtual {_implementation} function.
                                     *
                                     * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                                     * different contract through the {_delegate} function.
                                     *
                                     * The success and return data of the delegated call will be returned back to the caller of the proxy.
                                     */
                                    abstract contract Proxy {
                                        /**
                                         * @dev Delegates the current call to `implementation`.
                                         *
                                         * This function does not return to its internal call site, it will return directly to the external caller.
                                         */
                                        function _delegate(address implementation) internal virtual {
                                            assembly {
                                                // Copy msg.data. We take full control of memory in this inline assembly
                                                // block because it will not return to Solidity code. We overwrite the
                                                // Solidity scratch pad at memory position 0.
                                                calldatacopy(0, 0, calldatasize())
                                                // Call the implementation.
                                                // out and outsize are 0 because we don't know the size yet.
                                                let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                                // Copy the returned data.
                                                returndatacopy(0, 0, returndatasize())
                                                switch result
                                                // delegatecall returns 0 on error.
                                                case 0 {
                                                    revert(0, returndatasize())
                                                }
                                                default {
                                                    return(0, returndatasize())
                                                }
                                            }
                                        }
                                        /**
                                         * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
                                         * and {_fallback} should delegate.
                                         */
                                        function _implementation() internal view virtual returns (address);
                                        /**
                                         * @dev Delegates the current call to the address returned by `_implementation()`.
                                         *
                                         * This function does not return to its internall call site, it will return directly to the external caller.
                                         */
                                        function _fallback() internal virtual {
                                            _beforeFallback();
                                            _delegate(_implementation());
                                        }
                                        /**
                                         * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                                         * function in the contract matches the call data.
                                         */
                                        fallback() external payable virtual {
                                            _fallback();
                                        }
                                        /**
                                         * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                                         * is empty.
                                         */
                                        receive() external payable virtual {
                                            _fallback();
                                        }
                                        /**
                                         * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                                         * call, or as part of the Solidity `fallback` or `receive` functions.
                                         *
                                         * If overriden should call `super._beforeFallback()`.
                                         */
                                        function _beforeFallback() internal virtual {}
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev This is the interface that {BeaconProxy} expects of its beacon.
                                     */
                                    interface IBeacon {
                                        /**
                                         * @dev Must return an address that can be used as a delegate call target.
                                         *
                                         * {BeaconProxy} will check that this address is a contract.
                                         */
                                        function implementation() external view returns (address);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts (last updated v4.5.0-rc.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 (utils/StorageSlot.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev Library for reading and writing primitive types to specific storage slots.
                                     *
                                     * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
                                     * This library helps with reading and writing to such slots without the need for inline assembly.
                                     *
                                     * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
                                     *
                                     * Example usage to set ERC1967 implementation slot:
                                     * ```
                                     * contract ERC1967 {
                                     *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                     *
                                     *     function _getImplementation() internal view returns (address) {
                                     *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                     *     }
                                     *
                                     *     function _setImplementation(address newImplementation) internal {
                                     *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                     *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                     *     }
                                     * }
                                     * ```
                                     *
                                     * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
                                     */
                                    library StorageSlot {
                                        struct AddressSlot {
                                            address value;
                                        }
                                        struct BooleanSlot {
                                            bool value;
                                        }
                                        struct Bytes32Slot {
                                            bytes32 value;
                                        }
                                        struct Uint256Slot {
                                            uint256 value;
                                        }
                                        /**
                                         * @dev Returns an `AddressSlot` with member `value` located at `slot`.
                                         */
                                        function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                                            assembly {
                                                r.slot := slot
                                            }
                                        }
                                        /**
                                         * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                                         */
                                        function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                                            assembly {
                                                r.slot := slot
                                            }
                                        }
                                        /**
                                         * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                                         */
                                        function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                                            assembly {
                                                r.slot := slot
                                            }
                                        }
                                        /**
                                         * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                                         */
                                        function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                                            assembly {
                                                r.slot := slot
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (proxy/transparent/TransparentUpgradeableProxy.sol)
                                    pragma solidity ^0.8.0;
                                    import "../openzeppelin/proxy/ERC1967/ERC1967Proxy.sol";
                                    /**
                                     * @dev This contract implements a proxy that is upgradeable by an admin.
                                     *
                                     * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
                                     * clashing], which can potentially be used in an attack, this contract uses the
                                     * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
                                     * things that go hand in hand:
                                     *
                                     * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
                                     * that call matches one of the admin functions exposed by the proxy itself.
                                     * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
                                     * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
                                     * "admin cannot fallback to proxy target".
                                     *
                                     * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
                                     * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
                                     * to sudden errors when trying to call a function from the proxy implementation.
                                     *
                                     * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
                                     * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
                                     */
                                    contract OptimizedTransparentUpgradeableProxy is ERC1967Proxy {
                                        address internal immutable _ADMIN;
                                        /**
                                         * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
                                         * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
                                         */
                                        constructor(
                                            address _logic,
                                            address admin_,
                                            bytes memory _data
                                        ) payable ERC1967Proxy(_logic, _data) {
                                            assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
                                            _ADMIN = admin_;
                                            // still store it to work with EIP-1967
                                            bytes32 slot = _ADMIN_SLOT;
                                            // solhint-disable-next-line no-inline-assembly
                                            assembly {
                                                sstore(slot, admin_)
                                            }
                                            emit AdminChanged(address(0), admin_);
                                        }
                                        /**
                                         * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
                                         */
                                        modifier ifAdmin() {
                                            if (msg.sender == _getAdmin()) {
                                                _;
                                            } else {
                                                _fallback();
                                            }
                                        }
                                        /**
                                         * @dev Returns the current admin.
                                         *
                                         * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
                                         *
                                         * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                                         * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                                         * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
                                         */
                                        function admin() external ifAdmin returns (address admin_) {
                                            admin_ = _getAdmin();
                                        }
                                        /**
                                         * @dev Returns the current implementation.
                                         *
                                         * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
                                         *
                                         * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                                         * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                                         * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
                                         */
                                        function implementation() external ifAdmin returns (address implementation_) {
                                            implementation_ = _implementation();
                                        }
                                        /**
                                         * @dev Upgrade the implementation of the proxy.
                                         *
                                         * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
                                         */
                                        function upgradeTo(address newImplementation) external ifAdmin {
                                            _upgradeToAndCall(newImplementation, bytes(""), false);
                                        }
                                        /**
                                         * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
                                         * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
                                         * proxied contract.
                                         *
                                         * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
                                         */
                                        function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
                                            _upgradeToAndCall(newImplementation, data, true);
                                        }
                                        /**
                                         * @dev Returns the current admin.
                                         */
                                        function _admin() internal view virtual returns (address) {
                                            return _getAdmin();
                                        }
                                        /**
                                         * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
                                         */
                                        function _beforeFallback() internal virtual override {
                                            require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                                            super._beforeFallback();
                                        }
                                        function _getAdmin() internal view virtual override returns (address) {
                                            return _ADMIN;
                                        }
                                    }
                                    

                                    File 11 of 12: VerifierFeeLib
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity ^0.8.0;
                                    library CalldataBytesLib {
                                        function toU8(bytes calldata _bytes, uint _start) internal pure returns (uint8) {
                                            return uint8(_bytes[_start]);
                                        }
                                        function toU16(bytes calldata _bytes, uint _start) internal pure returns (uint16) {
                                            unchecked {
                                                uint end = _start + 2;
                                                return uint16(bytes2(_bytes[_start:end]));
                                            }
                                        }
                                        function toU32(bytes calldata _bytes, uint _start) internal pure returns (uint32) {
                                            unchecked {
                                                uint end = _start + 4;
                                                return uint32(bytes4(_bytes[_start:end]));
                                            }
                                        }
                                        function toU64(bytes calldata _bytes, uint _start) internal pure returns (uint64) {
                                            unchecked {
                                                uint end = _start + 8;
                                                return uint64(bytes8(_bytes[_start:end]));
                                            }
                                        }
                                        function toU128(bytes calldata _bytes, uint _start) internal pure returns (uint128) {
                                            unchecked {
                                                uint end = _start + 16;
                                                return uint128(bytes16(_bytes[_start:end]));
                                            }
                                        }
                                        function toU256(bytes calldata _bytes, uint _start) internal pure returns (uint256) {
                                            unchecked {
                                                uint end = _start + 32;
                                                return uint256(bytes32(_bytes[_start:end]));
                                            }
                                        }
                                        function toAddr(bytes calldata _bytes, uint _start) internal pure returns (address) {
                                            unchecked {
                                                uint end = _start + 20;
                                                return address(bytes20(_bytes[_start:end]));
                                            }
                                        }
                                        function toB32(bytes calldata _bytes, uint _start) internal pure returns (bytes32) {
                                            unchecked {
                                                uint end = _start + 32;
                                                return bytes32(_bytes[_start:end]);
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity ^0.8.0;
                                    library Errors {
                                        // Invalid Argument (http: 400)
                                        string internal constant INVALID_ARGUMENT = "LZ10000";
                                        string internal constant ONLY_REGISTERED = "LZ10001";
                                        string internal constant ONLY_REGISTERED_OR_DEFAULT = "LZ10002";
                                        string internal constant INVALID_AMOUNT = "LZ10003";
                                        string internal constant INVALID_NONCE = "LZ10004";
                                        string internal constant SAME_VALUE = "LZ10005";
                                        string internal constant UNSORTED = "LZ10006";
                                        string internal constant INVALID_VERSION = "LZ10007";
                                        string internal constant INVALID_EID = "LZ10008";
                                        string internal constant INVALID_SIZE = "LZ10009";
                                        string internal constant ONLY_NON_DEFAULT = "LZ10010";
                                        string internal constant INVALID_VERIFIERS = "LZ10011";
                                        string internal constant INVALID_WORKER_ID = "LZ10012";
                                        string internal constant DUPLICATED_OPTION = "LZ10013";
                                        string internal constant INVALID_LEGACY_OPTION = "LZ10014";
                                        string internal constant INVALID_VERIFIER_OPTION = "LZ10015";
                                        string internal constant INVALID_WORKER_OPTIONS = "LZ10016";
                                        string internal constant INVALID_EXECUTOR_OPTION = "LZ10017";
                                        string internal constant INVALID_ADDRESS = "LZ10018";
                                        // Out of Range (http: 400)
                                        string internal constant OUT_OF_RANGE = "LZ20000";
                                        // Invalid State (http: 400)
                                        string internal constant INVALID_STATE = "LZ30000";
                                        string internal constant SEND_REENTRANCY = "LZ30001";
                                        string internal constant RECEIVE_REENTRANCY = "LZ30002";
                                        string internal constant COMPOSE_REENTRANCY = "LZ30003";
                                        // Permission Denied (http: 403)
                                        string internal constant PERMISSION_DENIED = "LZ50000";
                                        // Not Found (http: 404)
                                        string internal constant NOT_FOUND = "LZ60000";
                                        // Already Exists (http: 409)
                                        string internal constant ALREADY_EXISTS = "LZ80000";
                                        // Not Implemented (http: 501)
                                        string internal constant NOT_IMPLEMENTED = "LZC0000";
                                        string internal constant UNSUPPORTED_INTERFACE = "LZC0001";
                                        string internal constant UNSUPPORTED_OPTION_TYPE = "LZC0002";
                                        // Unavailable (http: 503)
                                        string internal constant UNAVAILABLE = "LZD0000";
                                        string internal constant NATIVE_COIN_UNAVAILABLE = "LZD0001";
                                        string internal constant TOKEN_UNAVAILABLE = "LZD0002";
                                        string internal constant DEFAULT_LIBRARY_UNAVAILABLE = "LZD0003";
                                        string internal constant VERIFIERS_UNAVAILABLE = "LZD0004";
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    // modified from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/structs/BitMaps.sol
                                    pragma solidity ^0.8.19;
                                    library BitMaps {
                                        type BitMap256 is uint;
                                        /**
                                         * @dev Returns whether the bit at `index` is set.
                                         */
                                        function get(BitMap256 bitmap, uint8 index) internal pure returns (bool) {
                                            uint256 mask = 1 << index;
                                            return BitMap256.unwrap(bitmap) & mask != 0;
                                        }
                                        /**
                                         * @dev Sets the bit at `index`.
                                         */
                                        function set(BitMap256 bitmap, uint8 index) internal pure returns (BitMap256) {
                                            uint256 mask = 1 << index;
                                            return BitMap256.wrap(BitMap256.unwrap(bitmap) | mask);
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
                                    pragma solidity ^0.8.0;
                                    import "./IERC165.sol";
                                    /**
                                     * @dev Implementation of the {IERC165} interface.
                                     *
                                     * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
                                     * for the additional interface id that will be supported. For example:
                                     *
                                     * ```solidity
                                     * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                                     *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
                                     * }
                                     * ```
                                     *
                                     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
                                     */
                                    abstract contract ERC165 is IERC165 {
                                        /**
                                         * @dev See {IERC165-supportsInterface}.
                                         */
                                        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                                            return interfaceId == type(IERC165).interfaceId;
                                        }
                                    }
                                    // SPDX-License-Identifier: MIT
                                    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
                                    pragma solidity ^0.8.0;
                                    /**
                                     * @dev Interface of the ERC165 standard, as defined in the
                                     * https://eips.ethereum.org/EIPS/eip-165[EIP].
                                     *
                                     * Implementers can declare support of contract interfaces, which can then be
                                     * queried by others ({ERC165Checker}).
                                     *
                                     * For an implementation, see {ERC165}.
                                     */
                                    interface IERC165 {
                                        /**
                                         * @dev Returns true if this contract implements the interface defined by
                                         * `interfaceId`. See the corresponding
                                         * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                                         * to learn more about how these ids are created.
                                         *
                                         * This function call must use less than 30 000 gas.
                                         */
                                        function supportsInterface(bytes4 interfaceId) external view returns (bool);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface ILayerZeroPriceFeed {
                                        /**
                                         * @dev
                                         * priceRatio: (USD price of 1 unit of remote native token in unit of local native token) * PRICE_RATIO_DENOMINATOR
                                         */
                                        struct Price {
                                            uint128 priceRatio; // float value * 10 ^ 20, decimal awared. for aptos to evm, the basis would be (10^18 / 10^8) * 10 ^20 = 10 ^ 30.
                                            uint64 gasPriceInUnit; // for evm, it is in wei, for aptos, it is in octas.
                                            uint32 gasPerByte;
                                        }
                                        struct UpdatePrice {
                                            uint32 eid;
                                            Price price;
                                        }
                                        /**
                                         * @dev
                                         *    ArbGasInfo.go:GetPricesInArbGas
                                         *
                                         */
                                        struct ArbitrumPriceExt {
                                            uint64 gasPerL2Tx; // L2 overhead
                                            uint32 gasPerL1CallDataByte;
                                        }
                                        struct UpdatePriceExt {
                                            uint32 eid;
                                            Price price;
                                            ArbitrumPriceExt extend;
                                        }
                                        function nativeTokenPriceUSD() external view returns (uint128);
                                        function getFee(uint32 _dstEid, uint _callDataSize, uint _gas) external view returns (uint);
                                        function getPrice(uint32 _dstEid) external view returns (Price memory);
                                        function getPriceRatioDenominator() external view returns (uint128);
                                        function estimateFeeByEid(
                                            uint32 _dstEid,
                                            uint _callDataSize,
                                            uint _gas
                                        ) external view returns (uint fee, uint128 priceRatio, uint128 priceRatioDenominator, uint128 nativePriceUSD);
                                        function estimateFeeOnSend(
                                            uint32 _dstEid,
                                            uint _callDataSize,
                                            uint _gas
                                        ) external payable returns (uint fee, uint128 priceRatio, uint128 priceRatioDenominator, uint128 nativePriceUSD);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface IWorker {
                                        event SetWorkerLib(address workerLib);
                                        event SetPriceFeed(address priceFeed);
                                        event SetDefaultMultiplierBps(uint16 multiplierBps);
                                        event Withdraw(address lib, address to, uint amount);
                                        function setPriceFeed(address _priceFeed) external;
                                        function priceFeed() external view returns (address);
                                        function setDefaultMultiplierBps(uint16 _multiplierBps) external;
                                        function defaultMultiplierBps() external view returns (uint16);
                                        function withdrawFee(address _lib, address _to, uint _amount) external;
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity ^0.8.19;
                                    import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
                                    import "@layerzerolabs/lz-evm-protocol-v2/contracts/messagelib/libs/BitMaps.sol";
                                    import "../interfaces/ILayerZeroPriceFeed.sol";
                                    import "./interfaces/IVerifier.sol";
                                    import "./interfaces/IVerifierFeeLib.sol";
                                    import "./libs/VerifierOptions.sol";
                                    contract VerifierFeeLib is IVerifierFeeLib {
                                        using BitMaps for BitMaps.BitMap256;
                                        using VerifierOptions for bytes;
                                        uint16 internal constant EXECUTE_FIXED_BYTES = 68; // encoded: funcSigHash + params -> 4  + (32 * 2)
                                        uint16 internal constant SIGNATURE_RAW_BYTES = 65; // not encoded
                                        // callData(updateHash) = 132 (4 + 32 * 4), padded to 32 = 160 and encoded as bytes with an 64 byte overhead = 224
                                        uint16 internal constant UPDATE_HASH_BYTES = 224;
                                        uint internal constant NATIVE_DECIMALS_RATE = 1e18;
                                        // ========================= External =========================
                                        /// @dev get fee function that can change state. e.g. paying priceFeed
                                        /// @param _params fee params
                                        /// @param _dstConfig dst config
                                        /// @param //_options options
                                        function getFeeOnSend(
                                            FeeParams memory _params,
                                            IVerifier.DstConfig memory _dstConfig,
                                            bytes memory /* _options */
                                        ) external payable returns (uint) {
                                            uint callDataSize = _getCallDataSize(_params.quorum);
                                            // for future versions where priceFeed charges a fee
                                            //        uint priceFeedFee = ILayerZeroPriceFeed(_params.priceFeed).getFee(_params.dstEid, callDataSize, _dstConfig.gas);
                                            //        (uint fee, , , uint128 nativePriceUSD) = ILayerZeroPriceFeed(_params.priceFeed).estimateFeeOnSend{
                                            //            value: priceFeedFee
                                            //        }(_params.dstEid, callDataSize, _dstConfig.gas);
                                            (uint fee, , , uint128 nativePriceUSD) = ILayerZeroPriceFeed(_params.priceFeed).estimateFeeOnSend(
                                                _params.dstEid,
                                                callDataSize,
                                                _dstConfig.gas
                                            );
                                            return
                                                _applyPremium(
                                                    fee,
                                                    _dstConfig.multiplierBps,
                                                    _params.defaultMultiplierBps,
                                                    _dstConfig.floorMarginUSD,
                                                    nativePriceUSD
                                                );
                                        }
                                        // ========================= View =========================
                                        /// @dev get fee view function
                                        /// @param _params fee params
                                        /// @param _dstConfig dst config
                                        /// @param //_options options
                                        function getFee(
                                            FeeParams calldata _params,
                                            IVerifier.DstConfig calldata _dstConfig,
                                            bytes calldata /* _options */
                                        ) external view returns (uint) {
                                            uint callDataSize = _getCallDataSize(_params.quorum);
                                            (uint fee, , , uint128 nativePriceUSD) = ILayerZeroPriceFeed(_params.priceFeed).estimateFeeByEid(
                                                _params.dstEid,
                                                callDataSize,
                                                _dstConfig.gas
                                            );
                                            return
                                                _applyPremium(
                                                    fee,
                                                    _dstConfig.multiplierBps,
                                                    _params.defaultMultiplierBps,
                                                    _dstConfig.floorMarginUSD,
                                                    nativePriceUSD
                                                );
                                        }
                                        // ========================= Internal =========================
                                        function _getCallDataSize(uint _quorum) internal pure returns (uint) {
                                            uint totalSignatureBytes = _quorum * SIGNATURE_RAW_BYTES;
                                            if (totalSignatureBytes % 32 != 0) {
                                                totalSignatureBytes = totalSignatureBytes - (totalSignatureBytes % 32) + 32;
                                            }
                                            // getFee should charge on execute(updateHash)
                                            // totalSignatureBytesPadded also has 64 overhead for bytes
                                            return uint(EXECUTE_FIXED_BYTES) + UPDATE_HASH_BYTES + totalSignatureBytes + 64;
                                        }
                                        function _applyPremium(
                                            uint _fee,
                                            uint16 _bps,
                                            uint16 _defaultBps,
                                            uint128 _marginUSD,
                                            uint128 _nativePriceUSD
                                        ) internal pure returns (uint) {
                                            uint16 multiplierBps = _bps == 0 ? _defaultBps : _bps;
                                            uint feeWithMultiplier = (_fee * multiplierBps) / 10000;
                                            if (_nativePriceUSD == 0 || _marginUSD == 0) {
                                                return feeWithMultiplier;
                                            }
                                            uint feeWithFloorMargin = _fee + (_marginUSD * NATIVE_DECIMALS_RATE) / _nativePriceUSD;
                                            return feeWithFloorMargin > feeWithMultiplier ? feeWithFloorMargin : feeWithMultiplier;
                                        }
                                        // todo: add to getFee and getFeeOnSend
                                        function _decodeVerifierOptions(bytes calldata _options) internal pure returns (uint totalFee) {
                                            BitMaps.BitMap256 bitmap;
                                            uint cursor;
                                            while (cursor < _options.length) {
                                                (uint8 optionType, , uint newCursor) = _options.nextVerifierOption(cursor);
                                                cursor = newCursor;
                                                // check if option type is duplicated
                                                require(!bitmap.get(optionType), Errors.DUPLICATED_OPTION);
                                                bitmap = bitmap.set(optionType);
                                                if (optionType == VerifierOptions.OPTION_TYPE_PRECRIME) {
                                                    totalFee += 100; //todo: confirm fee
                                                } else {
                                                    revert("VerifierFeeLib: invalid option type");
                                                }
                                            }
                                            require(cursor == _options.length, Errors.INVALID_VERIFIER_OPTION);
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    interface ILayerZeroVerifier {
                                        struct AssignJobParam {
                                            uint32 dstEid;
                                            bytes packetHeader;
                                            bytes32 payloadHash;
                                            uint64 confirmations;
                                            address sender;
                                        }
                                        // @notice query price and assign jobs at the same time
                                        // @param _dstEid - the destination endpoint identifier
                                        // @param _packetHeader - version + nonce + path
                                        // @param _payloadHash - hash of guid + message
                                        // @param _confirmations - block confirmation delay before relaying blocks
                                        // @param _sender - the source sending contract address
                                        // @param _options - options
                                        function assignJob(AssignJobParam calldata _param, bytes calldata _options) external payable returns (uint fee);
                                        // @notice query the verifier fee for relaying block information to the destination chain
                                        // @param _dstEid the destination endpoint identifier
                                        // @param _confirmations - block confirmation delay before relaying blocks
                                        // @param _sender - the source sending contract address
                                        // @param _options - options
                                        function getFee(
                                            uint32 _dstEid,
                                            uint64 _confirmations,
                                            address _sender,
                                            bytes calldata _options
                                        ) external view returns (uint fee);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    import "../../interfaces/IWorker.sol";
                                    import "./ILayerZeroVerifier.sol";
                                    interface IVerifier is IWorker, ILayerZeroVerifier {
                                        struct DstConfigParam {
                                            uint32 dstEid;
                                            uint64 gas;
                                            uint16 multiplierBps;
                                            uint128 floorMarginUSD;
                                        }
                                        struct DstConfig {
                                            uint64 gas;
                                            uint16 multiplierBps;
                                            uint128 floorMarginUSD; // uses priceFeed PRICE_RATIO_DENOMINATOR
                                        }
                                        event SetDstConfig(DstConfigParam[] params);
                                        function dstConfig(uint32 _dstEid) external view returns (uint64, uint16, uint128);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.8.0;
                                    import "./IVerifier.sol";
                                    interface IVerifierFeeLib {
                                        struct FeeParams {
                                            address priceFeed;
                                            uint32 dstEid;
                                            uint64 confirmations;
                                            address sender;
                                            uint64 quorum;
                                            uint16 defaultMultiplierBps;
                                        }
                                        function getFeeOnSend(
                                            FeeParams memory _params,
                                            IVerifier.DstConfig memory _dstConfig,
                                            bytes memory _options
                                        ) external payable returns (uint fee);
                                        function getFee(
                                            FeeParams calldata _params,
                                            IVerifier.DstConfig calldata _dstConfig,
                                            bytes calldata _options
                                        ) external view returns (uint fee);
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity ^0.8.0;
                                    import "solidity-bytes-utils/contracts/BytesLib.sol";
                                    import "@layerzerolabs/lz-evm-protocol-v2/contracts/messagelib/libs/BitMaps.sol";
                                    import "@layerzerolabs/lz-evm-protocol-v2/contracts/libs/Errors.sol";
                                    import "@layerzerolabs/lz-evm-protocol-v2/contracts/libs/CalldataBytesLib.sol";
                                    library VerifierOptions {
                                        using BitMaps for BitMaps.BitMap256;
                                        using CalldataBytesLib for bytes;
                                        using BytesLib for bytes;
                                        uint8 internal constant WORKER_ID = 2;
                                        uint8 internal constant OPTION_TYPE_PRECRIME = 1;
                                        /// @dev group verifier options by its idx
                                        /// @param _options [verifier_id][verifier_option][verifier_id][verifier_option]...
                                        ///        verifier_option = [option_size][verifier_idx][option_type][option]
                                        ///        option_size = len(verifier_idx) + len(option_type) + len(option)
                                        ///        verifier_id: uint8, verifier_idx: uint8, option_size: uint16, option_type: uint8, option: bytes
                                        /// @return verifierOptions the grouped options, still share the same format of _options
                                        /// @return verifierIndices the verifier indices
                                        function groupVerifierOptionsByIdx(
                                            bytes memory _options
                                        ) internal pure returns (bytes[] memory verifierOptions, uint8[] memory verifierIndices) {
                                            if (_options.length == 0) return (verifierOptions, verifierIndices);
                                            uint8 numVerifiers = getNumVerifiers(_options);
                                            // if there is only 1 verifier, we can just return the whole options
                                            if (numVerifiers == 1) {
                                                verifierOptions = new bytes[](1);
                                                verifierOptions[0] = _options;
                                                verifierIndices = new uint8[](1);
                                                verifierIndices[0] = _options.toUint8(3); // verifier idx
                                                return (verifierOptions, verifierIndices);
                                            }
                                            // otherwise, we need to group the options by verifier_idx
                                            verifierIndices = new uint8[](numVerifiers);
                                            verifierOptions = new bytes[](numVerifiers);
                                            unchecked {
                                                uint cursor;
                                                uint start;
                                                uint8 lastVerifierIdx = 255; // 255 is an invalid verifier_idx
                                                while (cursor < _options.length) {
                                                    ++cursor; // skip worker_id
                                                    // optionLength asserted in getNumVerifiers (skip check)
                                                    uint16 optionLength = _options.toUint16(cursor);
                                                    cursor += 2;
                                                    // verifierIdx asserted in getNumVerifiers (skip check)
                                                    uint8 verifierIdx = _options.toUint8(cursor);
                                                    // verifierIdx must equal to the lastVerifierIdx for the first option
                                                    // so it is always skipped in the first option
                                                    // this operation slices out options whenever the scan finds a different lastVerifierIdx
                                                    if (lastVerifierIdx == 255) {
                                                        lastVerifierIdx = verifierIdx;
                                                    } else if (verifierIdx != lastVerifierIdx) {
                                                        uint len = cursor - start - 3; // 3 is for worker_id and option_length
                                                        bytes memory opt = _options.slice(start, len);
                                                        _insertVerifierOptions(verifierOptions, verifierIndices, lastVerifierIdx, opt);
                                                        // reset the start and lastVerifierIdx
                                                        start += len;
                                                        lastVerifierIdx = verifierIdx;
                                                    }
                                                    cursor += optionLength;
                                                }
                                                // skip check the cursor here because the cursor is asserted in getNumVerifiers
                                                // if we have reached the end of the options, we need to process the last verifier
                                                uint size = cursor - start;
                                                bytes memory op = _options.slice(start, size);
                                                _insertVerifierOptions(verifierOptions, verifierIndices, lastVerifierIdx, op);
                                                // revert verifierIndices to start from 0
                                                for (uint8 i = 0; i < numVerifiers; ++i) {
                                                    --verifierIndices[i];
                                                }
                                            }
                                        }
                                        function _insertVerifierOptions(
                                            bytes[] memory _verifierOptions,
                                            uint8[] memory _verifierIndices,
                                            uint8 _verifierIdx,
                                            bytes memory _newOptions
                                        ) internal pure {
                                            unchecked {
                                                // verifierIdx starts from 0 but default value of verifierIndices is 0,
                                                // so we tell if the slot is empty by adding 1 to verifierIdx
                                                require(_verifierIdx < 255, Errors.INVALID_VERIFIERS);
                                                uint8 verifierIdxAdj = _verifierIdx + 1;
                                                for (uint8 j = 0; j < _verifierIndices.length; ++j) {
                                                    uint8 index = _verifierIndices[j];
                                                    if (verifierIdxAdj == index) {
                                                        _verifierOptions[j] = abi.encodePacked(_verifierOptions[j], _newOptions);
                                                        break;
                                                    } else if (index == 0) {
                                                        // empty slot, that means it is the first time we see this verifier
                                                        _verifierIndices[j] = verifierIdxAdj;
                                                        _verifierOptions[j] = _newOptions;
                                                        break;
                                                    }
                                                }
                                            }
                                        }
                                        /// @dev get the number of unique verifiers
                                        /// @param _options the format is the same as groupVerifierOptionsByIdx
                                        function getNumVerifiers(bytes memory _options) internal pure returns (uint8 numVerifiers) {
                                            uint cursor;
                                            BitMaps.BitMap256 bitmap;
                                            // find number of unique verifier_idx
                                            unchecked {
                                                while (cursor < _options.length) {
                                                    ++cursor; // skip worker_id
                                                    uint16 optionLength = _options.toUint16(cursor);
                                                    cursor += 2;
                                                    require(optionLength >= 2, Errors.INVALID_VERIFIER_OPTION); // at least 1 byte for verifier_idx and 1 byte for option_type
                                                    uint8 verifierIdx = _options.toUint8(cursor);
                                                    // if verifierIdx is not set, increment numVerifiers
                                                    // max num of verifiers is 255, 255 is an invalid verifier_idx
                                                    require(verifierIdx < 255, Errors.INVALID_VERIFIERS);
                                                    if (!bitmap.get(verifierIdx)) {
                                                        ++numVerifiers;
                                                        bitmap = bitmap.set(verifierIdx);
                                                    }
                                                    cursor += optionLength;
                                                }
                                            }
                                            require(cursor == _options.length, Errors.INVALID_VERIFIER_OPTION);
                                        }
                                        /// @dev decode the next verifier option from _options starting from the specified cursor
                                        /// @param _options the format is the same as groupVerifierOptionsByIdx
                                        /// @param _cursor the cursor to start decoding
                                        /// @return optionType the type of the option
                                        /// @return option the option
                                        /// @return cursor the cursor to start decoding the next option
                                        function nextVerifierOption(
                                            bytes calldata _options,
                                            uint _cursor
                                        ) internal pure returns (uint8 optionType, bytes calldata option, uint cursor) {
                                            unchecked {
                                                // skip worker id
                                                cursor = _cursor + 1;
                                                // read option size
                                                uint16 size = _options.toU16(cursor);
                                                cursor += 2;
                                                // read option type
                                                optionType = _options.toU8(cursor + 1); // skip verifier_idx
                                                // startCursor and endCursor are used to slice the option from _options
                                                uint startCursor = cursor + 2; // skip option type and verifier_idx
                                                uint endCursor = cursor + size;
                                                option = _options[startCursor:endCursor];
                                                cursor += size;
                                            }
                                        }
                                    }
                                    // SPDX-License-Identifier: Unlicense
                                    /*
                                     * @title Solidity Bytes Arrays Utils
                                     * @author Gonçalo Sá <[email protected]>
                                     *
                                     * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
                                     *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
                                     */
                                    pragma solidity >=0.8.0 <0.9.0;
                                    library BytesLib {
                                        function concat(
                                            bytes memory _preBytes,
                                            bytes memory _postBytes
                                        )
                                            internal
                                            pure
                                            returns (bytes memory)
                                        {
                                            bytes memory tempBytes;
                                            assembly {
                                                // Get a location of some free memory and store it in tempBytes as
                                                // Solidity does for memory variables.
                                                tempBytes := mload(0x40)
                                                // Store the length of the first bytes array at the beginning of
                                                // the memory for tempBytes.
                                                let length := mload(_preBytes)
                                                mstore(tempBytes, length)
                                                // Maintain a memory counter for the current write location in the
                                                // temp bytes array by adding the 32 bytes for the array length to
                                                // the starting location.
                                                let mc := add(tempBytes, 0x20)
                                                // Stop copying when the memory counter reaches the length of the
                                                // first bytes array.
                                                let end := add(mc, length)
                                                for {
                                                    // Initialize a copy counter to the start of the _preBytes data,
                                                    // 32 bytes into its memory.
                                                    let cc := add(_preBytes, 0x20)
                                                } lt(mc, end) {
                                                    // Increase both counters by 32 bytes each iteration.
                                                    mc := add(mc, 0x20)
                                                    cc := add(cc, 0x20)
                                                } {
                                                    // Write the _preBytes data into the tempBytes memory 32 bytes
                                                    // at a time.
                                                    mstore(mc, mload(cc))
                                                }
                                                // Add the length of _postBytes to the current length of tempBytes
                                                // and store it as the new length in the first 32 bytes of the
                                                // tempBytes memory.
                                                length := mload(_postBytes)
                                                mstore(tempBytes, add(length, mload(tempBytes)))
                                                // Move the memory counter back from a multiple of 0x20 to the
                                                // actual end of the _preBytes data.
                                                mc := end
                                                // Stop copying when the memory counter reaches the new combined
                                                // length of the arrays.
                                                end := add(mc, length)
                                                for {
                                                    let cc := add(_postBytes, 0x20)
                                                } lt(mc, end) {
                                                    mc := add(mc, 0x20)
                                                    cc := add(cc, 0x20)
                                                } {
                                                    mstore(mc, mload(cc))
                                                }
                                                // Update the free-memory pointer by padding our last write location
                                                // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
                                                // next 32 byte block, then round down to the nearest multiple of
                                                // 32. If the sum of the length of the two arrays is zero then add
                                                // one before rounding down to leave a blank 32 bytes (the length block with 0).
                                                mstore(0x40, and(
                                                  add(add(end, iszero(add(length, mload(_preBytes)))), 31),
                                                  not(31) // Round down to the nearest 32 bytes.
                                                ))
                                            }
                                            return tempBytes;
                                        }
                                        function concatStorage(bytes storage _preBytes, bytes memory _postBytes) internal {
                                            assembly {
                                                // Read the first 32 bytes of _preBytes storage, which is the length
                                                // of the array. (We don't need to use the offset into the slot
                                                // because arrays use the entire slot.)
                                                let fslot := sload(_preBytes.slot)
                                                // Arrays of 31 bytes or less have an even value in their slot,
                                                // while longer arrays have an odd value. The actual length is
                                                // the slot divided by two for odd values, and the lowest order
                                                // byte divided by two for even values.
                                                // If the slot is even, bitwise and the slot with 255 and divide by
                                                // two to get the length. If the slot is odd, bitwise and the slot
                                                // with -1 and divide by two.
                                                let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                                                let mlength := mload(_postBytes)
                                                let newlength := add(slength, mlength)
                                                // slength can contain both the length and contents of the array
                                                // if length < 32 bytes so let's prepare for that
                                                // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                                                switch add(lt(slength, 32), lt(newlength, 32))
                                                case 2 {
                                                    // Since the new array still fits in the slot, we just need to
                                                    // update the contents of the slot.
                                                    // uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_length
                                                    sstore(
                                                        _preBytes.slot,
                                                        // all the modifications to the slot are inside this
                                                        // next block
                                                        add(
                                                            // we can just add to the slot contents because the
                                                            // bytes we want to change are the LSBs
                                                            fslot,
                                                            add(
                                                                mul(
                                                                    div(
                                                                        // load the bytes from memory
                                                                        mload(add(_postBytes, 0x20)),
                                                                        // zero all bytes to the right
                                                                        exp(0x100, sub(32, mlength))
                                                                    ),
                                                                    // and now shift left the number of bytes to
                                                                    // leave space for the length in the slot
                                                                    exp(0x100, sub(32, newlength))
                                                                ),
                                                                // increase length by the double of the memory
                                                                // bytes length
                                                                mul(mlength, 2)
                                                            )
                                                        )
                                                    )
                                                }
                                                case 1 {
                                                    // The stored value fits in the slot, but the combined value
                                                    // will exceed it.
                                                    // get the keccak hash to get the contents of the array
                                                    mstore(0x0, _preBytes.slot)
                                                    let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                                                    // save new length
                                                    sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                                                    // The contents of the _postBytes array start 32 bytes into
                                                    // the structure. Our first read should obtain the `submod`
                                                    // bytes that can fit into the unused space in the last word
                                                    // of the stored array. To get this, we read 32 bytes starting
                                                    // from `submod`, so the data we read overlaps with the array
                                                    // contents by `submod` bytes. Masking the lowest-order
                                                    // `submod` bytes allows us to add that value directly to the
                                                    // stored value.
                                                    let submod := sub(32, slength)
                                                    let mc := add(_postBytes, submod)
                                                    let end := add(_postBytes, mlength)
                                                    let mask := sub(exp(0x100, submod), 1)
                                                    sstore(
                                                        sc,
                                                        add(
                                                            and(
                                                                fslot,
                                                                0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
                                                            ),
                                                            and(mload(mc), mask)
                                                        )
                                                    )
                                                    for {
                                                        mc := add(mc, 0x20)
                                                        sc := add(sc, 1)
                                                    } lt(mc, end) {
                                                        sc := add(sc, 1)
                                                        mc := add(mc, 0x20)
                                                    } {
                                                        sstore(sc, mload(mc))
                                                    }
                                                    mask := exp(0x100, sub(mc, end))
                                                    sstore(sc, mul(div(mload(mc), mask), mask))
                                                }
                                                default {
                                                    // get the keccak hash to get the contents of the array
                                                    mstore(0x0, _preBytes.slot)
                                                    // Start copying to the last used word of the stored array.
                                                    let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                                                    // save new length
                                                    sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                                                    // Copy over the first `submod` bytes of the new data as in
                                                    // case 1 above.
                                                    let slengthmod := mod(slength, 32)
                                                    let mlengthmod := mod(mlength, 32)
                                                    let submod := sub(32, slengthmod)
                                                    let mc := add(_postBytes, submod)
                                                    let end := add(_postBytes, mlength)
                                                    let mask := sub(exp(0x100, submod), 1)
                                                    sstore(sc, add(sload(sc), and(mload(mc), mask)))
                                                    for {
                                                        sc := add(sc, 1)
                                                        mc := add(mc, 0x20)
                                                    } lt(mc, end) {
                                                        sc := add(sc, 1)
                                                        mc := add(mc, 0x20)
                                                    } {
                                                        sstore(sc, mload(mc))
                                                    }
                                                    mask := exp(0x100, sub(mc, end))
                                                    sstore(sc, mul(div(mload(mc), mask), mask))
                                                }
                                            }
                                        }
                                        function slice(
                                            bytes memory _bytes,
                                            uint256 _start,
                                            uint256 _length
                                        )
                                            internal
                                            pure
                                            returns (bytes memory)
                                        {
                                            require(_length + 31 >= _length, "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 toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
                                            require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
                                            address tempAddress;
                                            assembly {
                                                tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
                                            }
                                            return tempAddress;
                                        }
                                        function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
                                            require(_bytes.length >= _start + 1 , "toUint8_outOfBounds");
                                            uint8 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x1), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
                                            require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
                                            uint16 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x2), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint32(bytes memory _bytes, uint256 _start) internal pure returns (uint32) {
                                            require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
                                            uint32 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x4), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint64(bytes memory _bytes, uint256 _start) internal pure returns (uint64) {
                                            require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
                                            uint64 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x8), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint96(bytes memory _bytes, uint256 _start) internal pure returns (uint96) {
                                            require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
                                            uint96 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0xc), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint128(bytes memory _bytes, uint256 _start) internal pure returns (uint128) {
                                            require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
                                            uint128 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x10), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
                                            require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
                                            uint256 tempUint;
                                            assembly {
                                                tempUint := mload(add(add(_bytes, 0x20), _start))
                                            }
                                            return tempUint;
                                        }
                                        function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
                                            require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
                                            bytes32 tempBytes32;
                                            assembly {
                                                tempBytes32 := mload(add(add(_bytes, 0x20), _start))
                                            }
                                            return tempBytes32;
                                        }
                                        function equal(bytes memory _preBytes, bytes memory _postBytes) internal pure returns (bool) {
                                            bool success = true;
                                            assembly {
                                                let length := mload(_preBytes)
                                                // if lengths don't match the arrays are not equal
                                                switch eq(length, mload(_postBytes))
                                                case 1 {
                                                    // cb is a circuit breaker in the for loop since there's
                                                    //  no said feature for inline assembly loops
                                                    // cb = 1 - don't breaker
                                                    // cb = 0 - break
                                                    let cb := 1
                                                    let mc := add(_preBytes, 0x20)
                                                    let end := add(mc, length)
                                                    for {
                                                        let cc := add(_postBytes, 0x20)
                                                    // the next line is the loop condition:
                                                    // while(uint256(mc < end) + cb == 2)
                                                    } eq(add(lt(mc, end), cb), 2) {
                                                        mc := add(mc, 0x20)
                                                        cc := add(cc, 0x20)
                                                    } {
                                                        // if any of these checks fails then arrays are not equal
                                                        if iszero(eq(mload(mc), mload(cc))) {
                                                            // unsuccess:
                                                            success := 0
                                                            cb := 0
                                                        }
                                                    }
                                                }
                                                default {
                                                    // unsuccess:
                                                    success := 0
                                                }
                                            }
                                            return success;
                                        }
                                        function equalStorage(
                                            bytes storage _preBytes,
                                            bytes memory _postBytes
                                        )
                                            internal
                                            view
                                            returns (bool)
                                        {
                                            bool success = true;
                                            assembly {
                                                // we know _preBytes_offset is 0
                                                let fslot := sload(_preBytes.slot)
                                                // Decode the length of the stored array like in concatStorage().
                                                let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                                                let mlength := mload(_postBytes)
                                                // if lengths don't match the arrays are not equal
                                                switch eq(slength, mlength)
                                                case 1 {
                                                    // slength can contain both the length and contents of the array
                                                    // if length < 32 bytes so let's prepare for that
                                                    // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                                                    if iszero(iszero(slength)) {
                                                        switch lt(slength, 32)
                                                        case 1 {
                                                            // blank the last byte which is the length
                                                            fslot := mul(div(fslot, 0x100), 0x100)
                                                            if iszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
                                                                // unsuccess:
                                                                success := 0
                                                            }
                                                        }
                                                        default {
                                                            // cb is a circuit breaker in the for loop since there's
                                                            //  no said feature for inline assembly loops
                                                            // cb = 1 - don't breaker
                                                            // cb = 0 - break
                                                            let cb := 1
                                                            // get the keccak hash to get the contents of the array
                                                            mstore(0x0, _preBytes.slot)
                                                            let sc := keccak256(0x0, 0x20)
                                                            let mc := add(_postBytes, 0x20)
                                                            let end := add(mc, mlength)
                                                            // the next line is the loop condition:
                                                            // while(uint256(mc < end) + cb == 2)
                                                            for {} eq(add(lt(mc, end), cb), 2) {
                                                                sc := add(sc, 1)
                                                                mc := add(mc, 0x20)
                                                            } {
                                                                if iszero(eq(sload(sc), mload(mc))) {
                                                                    // unsuccess:
                                                                    success := 0
                                                                    cb := 0
                                                                }
                                                            }
                                                        }
                                                    }
                                                }
                                                default {
                                                    // unsuccess:
                                                    success := 0
                                                }
                                            }
                                            return success;
                                        }
                                    }
                                    

                                    File 12 of 12: TreasuryV2
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity 0.7.6;
                                    import "./interfaces/ILayerZeroTreasury.sol";
                                    import "@openzeppelin/contracts/access/Ownable.sol";
                                    import "@openzeppelin/contracts/math/SafeMath.sol";
                                    import "./interfaces/ILayerZeroUltraLightNodeV2.sol";
                                    contract TreasuryV2 is ILayerZeroTreasury, Ownable {
                                        using SafeMath for uint;
                                        uint public nativeBP;
                                        uint public zroFee;
                                        bool public feeEnabled;
                                        bool public zroEnabled;
                                        ILayerZeroUltraLightNodeV2 public uln;
                                        event NativeBP(uint bp);
                                        event ZroFee(uint zroFee);
                                        event FeeEnabled(bool feeEnabled);
                                        event ZroEnabled(bool zroEnabled);
                                        constructor(address _ulnv2) {
                                            uln = ILayerZeroUltraLightNodeV2(_ulnv2);
                                        }
                                        function getFees(bool payInZro, uint relayerFee, uint oracleFee) external view override returns (uint) {
                                            if (feeEnabled) {
                                                if (payInZro) {
                                                    require(zroEnabled, "LayerZero: ZRO is not enabled");
                                                    return zroFee;
                                                } else {
                                                    return relayerFee.add(oracleFee).mul(nativeBP).div(10000);
                                                }
                                            }
                                            return 0;
                                        }
                                        function setFeeEnabled(bool _feeEnabled) external onlyOwner {
                                            feeEnabled = _feeEnabled;
                                            emit FeeEnabled(_feeEnabled);
                                        }
                                        function setZroEnabled(bool _zroEnabled) external onlyOwner {
                                            zroEnabled = _zroEnabled;
                                            emit ZroEnabled(_zroEnabled);
                                        }
                                        function setNativeBP(uint _nativeBP) external onlyOwner {
                                            nativeBP = _nativeBP;
                                            emit NativeBP(_nativeBP);
                                        }
                                        function setZroFee(uint _zroFee) external onlyOwner {
                                            zroFee = _zroFee;
                                            emit ZroFee(_zroFee);
                                        }
                                        function withdrawZROFromULN(address _to, uint _amount) external onlyOwner {
                                            uln.withdrawZRO(_to, _amount);
                                        }
                                        function withdrawNativeFromULN(address payable _to, uint _amount) external onlyOwner {
                                            uln.withdrawNative(_to, _amount);
                                        }
                                    }
                                    // SPDX-License-Identifier: BUSL-1.1
                                    pragma solidity >=0.5.0;
                                    interface ILayerZeroTreasury {
                                        function getFees(bool payInZro, uint relayerFee, uint oracleFee) external view returns (uint);
                                    }
                                    // SPDX-License-Identifier: MIT
                                    pragma solidity ^0.7.0;
                                    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 ^0.7.0;
                                    /**
                                     * @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: BUSL-1.1
                                    pragma solidity >=0.7.0;
                                    pragma abicoder v2;
                                    interface ILayerZeroUltraLightNodeV2 {
                                        // Relayer functions
                                        function validateTransactionProof(uint16 _srcChainId, address _dstAddress, uint _gasLimit, bytes32 _lookupHash, bytes32 _blockData, bytes calldata _transactionProof) external;
                                        // an Oracle delivers the block data using updateHash()
                                        function updateHash(uint16 _srcChainId, bytes32 _lookupHash, uint _confirmations, bytes32 _blockData) external;
                                        // can only withdraw the receivable of the msg.sender
                                        function withdrawNative(address payable _to, uint _amount) external;
                                        function withdrawZRO(address _to, uint _amount) external;
                                        // view functions
                                        function getAppConfig(uint16 _remoteChainId, address _userApplicationAddress) external view returns (ApplicationConfiguration memory);
                                        function accruedNativeFee(address _address) external view returns (uint);
                                        struct ApplicationConfiguration {
                                            uint16 inboundProofLibraryVersion;
                                            uint64 inboundBlockConfirmations;
                                            address relayer;
                                            uint16 outboundProofType;
                                            uint64 outboundBlockConfirmations;
                                            address oracle;
                                        }
                                        event HashReceived(uint16 indexed srcChainId, address indexed oracle, bytes32 lookupHash, bytes32 blockData, uint confirmations);
                                        event RelayerParams(bytes adapterParams, uint16 outboundProofType);
                                        event Packet(bytes payload);
                                        event InvalidDst(uint16 indexed srcChainId, bytes srcAddress, address indexed dstAddress, uint64 nonce, bytes32 payloadHash);
                                        event PacketReceived(uint16 indexed srcChainId, bytes srcAddress, address indexed dstAddress, uint64 nonce, bytes32 payloadHash);
                                        event AppConfigUpdated(address indexed userApplication, uint indexed configType, bytes newConfig);
                                        event AddInboundProofLibraryForChain(uint16 indexed chainId, address lib);
                                        event EnableSupportedOutboundProof(uint16 indexed chainId, uint16 proofType);
                                        event SetChainAddressSize(uint16 indexed chainId, uint size);
                                        event SetDefaultConfigForChainId(uint16 indexed chainId, uint16 inboundProofLib, uint64 inboundBlockConfirm, address relayer, uint16 outboundProofType, uint64 outboundBlockConfirm, address oracle);
                                        event SetDefaultAdapterParamsForChainId(uint16 indexed chainId, uint16 indexed proofType, bytes adapterParams);
                                        event SetLayerZeroToken(address indexed tokenAddress);
                                        event SetRemoteUln(uint16 indexed chainId, bytes32 uln);
                                        event SetTreasury(address indexed treasuryAddress);
                                        event WithdrawZRO(address indexed msgSender, address indexed to, uint amount);
                                        event WithdrawNative(address indexed msgSender, address indexed to, uint amount);
                                    }
                                    // 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;
                                        }
                                    }