import 'models.dart'; abstract class MusicSource { Future ping(); Stream> allAlbums(); Stream> allArtists(); Stream> allPlaylists(); Stream> allSongs(); Stream> allPlaylistSongs(); Uri streamUri(String songId); Uri downloadUri(String songId); Uri coverArtUri(String coverArtId, {bool thumbnail = true}); Future artistArtUri(String artistId, {bool thumbnail = true}); }