interface IERC2981 is IERC165 {
    /// ERC165 bytes to add to interface array - set in parent contract
    /// implementing this standard
    ///
    /// bytes4(keccak256("royaltyInfo(uint256,uint256)")) == 0x2a55205a
    /// bytes4 private constant _INTERFACE_ID_ERC2981 = 0x2a55205a;
    /// _registerInterface(_INTERFACE_ID_ERC2981);

    /// @notice Called with the sale price to determine how much royalty
    //          is owed and to whom.
    /// @param _tokenId - the NFT asset queried for royalty information
    /// @param _salePrice - the sale price of the NFT asset specified by _tokenId
    /// @return receiver - address of who should be sent the royalty payment
    /// @return royaltyAmount - the royalty payment amount for _salePrice
    function royaltyInfo(
        uint256 _tokenId,
        uint256 _salePrice
    ) external view returns (
        address receiver,
        uint256 royaltyAmount
    );

}
///
/// @dev Interface for the NFT Royalty Standard
///
function royaltyInfo(
    uint256 _tokenId,
    uint256 _salePrice
) external view returns (
    address receiver,
    uint256 royaltyAmount
);

/// @param _tokenId - the NFT asset queried for royalty information
/// @param _salePrice - the sale price of the NFT asset specified by _tokenId
/// @return receiver - address of who should be sent the royalty payment
/// @return royaltyAmount - the royalty payment amount for _salePrice