        (inputToken, inputAmount, outputToken, outputAmount) = _executeInteraction(
                interaction, interactionType, externalContract, specifiedToken, interaction.specifiedAmount, userAddress
            );
        }

        // if _executeInteraction returned a positive value for inputAmount,
        // this amount must be deducted from the user's Ocean balance
        if (inputAmount > 0) {
            // since uint, same as (inputAmount != 0)
            _burn(userAddress, inputToken, inputAmount);
        }

        // if _executeInteraction returned a positive value for outputAmount,
        // this amount must be credited to the user's Ocean balance
        if (outputAmount > 0) {
            // since uint, same as (outputAmount != 0)
            _mint(userAddress, outputToken, outputAmount);
        }
    function _erc721Unwrap(address tokenAddress, uint256 tokenId, address userAddress, uint256 oceanId) private {
        IERC721(tokenAddress).safeTransferFrom(address(this), userAddress, tokenId);
        emit Erc721Unwrap(tokenAddress, tokenId, userAddress, oceanId);
    }
function onERC721Received(
        address _sender, address _from, uint256 _tokenId, bytes memory _data)
        external returns (bytes4 retval) {

        require(msg.sender == address(victim), "Nope");
        // Call the loan function
        return victim.onERC721Received.selector;
}
