// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity >=0.7.0 <0.9.0;

/// @dev Note: the ERC-165 identifier for this interface is 0x150b7a02.
interface ERC721TokenReceiver {
    /**
     * @notice Handle the receipt of an NFT
     * @dev The ERC721 smart contract calls this function on the recipient
     *  after a `transfer`. This function MAY throw to revert and reject the
     *  transfer. Return of other than the magic value MUST result in the
     *  transaction being reverted.
     *  Note: the contract address is always the message sender.
     * @param _operator The address which called `safeTransferFrom` function.
     * @param _from The address which previously owned the token.
     * @param _tokenId The NFT identifier which is being transferred.
     * @param _data Additional data with no specified format.
     * @return `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`.
     *  unless throwing
     */
    function onERC721Received(address _operator, address _from, uint256 _tokenId, bytes calldata _data) external returns (bytes4);
}