private static void HandleNullModel(ref Primitives.Playlist model, PlaylistPlaceholder placeholder)
 {
     if (model == null)
     {
         if (placeholder.Key == Primitives.Playlist.MusicLibraryPlaylistKey)
             model = Primitives.Playlist.CreateMusicLibrary();
         else
             model = new Primitives.Playlist
             {
                 Key = placeholder.Key,
                 Version = PlaylistVersions.Current
             };
     }
 }
 public PlaylistFile(Primitives.Playlist value)
 {
     if (value == null)
         throw new ArgumentNullException(nameof(value));
     _playlist = value;
 }
 public WatchedPlaylistProvider(Primitives.Playlist playlist)
 {
     _playlist = playlist;
     _folderDispatcher.PropertyChanged += _folderDispatcher_PropertyChanged;
 }