interface IMintableERC721 is IERC721 {
    /**
     * @notice called by predicate contract to mint tokens while withdrawing
     * @dev Should be callable only by MintableERC721Predicate
     * Make sure minting is done only by this function
     * @param user user address for whom token is being minted
     * @param tokenId tokenId being minted
     */
    function mint(address user, uint256 tokenId) external;

    /**
     * @notice called by predicate contract to mint tokens while withdrawing with metadata from L2
     * @dev Should be callable only by MintableERC721Predicate
     * Make sure minting is only done either by this function/ �
     * @param user user address for whom token is being minted
     * @param tokenId tokenId being minted
     * @param metaData Associated token metadata, to be decoded & set using `setTokenMetadata`
     *
     * Note : If you're interested in taking token metadata from L2 to L1 during exit, you must
     * implement this method
     */
    function mint(
        address user,
        uint256 tokenId,
        bytes calldata metaData
    ) external;

    /**
     * @notice check if token already exists, return true if it does exist
     * @dev this check will be used by the predicate to determine if the token needs to be minted or transfered
     * @param tokenId tokenId being checked
     */
    function exists(uint256 tokenId) external view returns (bool);
}
function exists(uint256 tokenId) external view returns (bool);

/**
 * @notice check if token already exists, return true if it does exist
 * @dev this check will be used by the predicate to determine if the token needs to be minted or transfered
 * @param tokenId tokenId being checked
 */