contract PixelDoorsv2 { // This doesn't have to match the real contract name. Call it what you like.
   function walletOfOwner (address _owner) public view returns (uint256[] memory) {} 
   function ownerOf (uint256) public view returns (address) {}
}
function walletOfOwner (address _owner) public view returns (uint256[] memory) {} 

// This doesn't have to match the real contract name. Call it what you like.