function lzReceive(
        uint16 _srcChainId,
        bytes memory _srcAddress,
        uint64 _nonce,
        bytes memory _payload
    ) external override {
        require(_msgSender() == address(endpoint), "!Endpoint");
        (bool success, bytes memory reason) = address(this).excessivelySafeCall(gasleft()*4/5, 150, abi.encodeWithSelector(this.nonblockingLzReceive.selector, _srcChainId, _srcAddress, _nonce, _payload));
        // try-catch all errors/exceptions
        if (!success) {
            failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(_payload);
            emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload, reason);
        }
    }
failedMessages[chainB][Bob's address][_nonce] = keccak256(_payload);
mapping(uint16 => mapping(bytes => mapping(uint64 => bool))) public consumedMessage;

    function lzReceive(
        uint16 _srcChainId,
        bytes memory _srcAddress,
        uint64 _nonce,
        bytes memory _payload
    ) external override {
        
        require(!consumedMessage[_srcChainId][_srcAddress][_nonce], "already consumed");
        consumedMessage[_srcChainId][_srcAddress][_nonce] = true;

        require(_msgSender() == address(endpoint), "!Endpoint");
        (bool success, bytes memory reason) = address(this).excessivelySafeCall(gasleft()*4/5, 150, abi.encodeWithSelector(this.nonblockingLzReceive.selector, _srcChainId, _srcAddress, _nonce, _payload));
        // try-catch all errors/exceptions
        if (!success) {
            failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(_payload);
            emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload, reason);
        }
    }
