Royalty problem at last line

I am trying to compile attaching royalty to compatible smart contract

:1234: Code to reproduce


bytes4 private constant _INTERFACE_ID_ERC2981 = 0x2a55205a;
 // Mappings _tokenID -> values
  mapping(uint256 => address) receiver;
  mapping(uint256 => uint256) royaltyPercentage;

  constructor() {

    // Using ERC165Storage set EIP-2981
    _registerInterface(_INTERFACE_ID_ERC2981);

  }

  // Set to be internal function _setReceiver
  function _setReceiver(uint256 _tokenId, address _address) internal {
    receiver[_tokenId] = _address;
  }

  // Set to be internal function _setRoyaltyPercentage
  function _setRoyaltyPercentage(uint256 _tokenId, uint256 _royaltyPercentage) internal {
    royaltyPercentage[_tokenId] = 2800; 

:computer: Environment

remix

Please provide all the relevant information, which should by the least include:

  • A proper description of what the problem actually is (in opposed to just saying that there IS a problem)

  • ALL the relevant code (for example, readers are not supposed to guess what _registerInterface is)

  • The error-message that you're getting (no one here can guess what it is)