private void AddNewPlaylist(object sender, System.Windows.RoutedEventArgs e)
 {
     if (PlaylistLibrary.Playlists == null)
     {
         PlaylistLibrary.Playlists = new Core.Utils.ObservableList <Playlist>();
         listPlaylists.ItemsSource = PlaylistLibrary.Playlists;
     }
     if (addPlaylist == null)
     {
         addPlaylist = new AddPlaylist();
         addPlaylist.Show();
     }
 }
 public void PlaylistAddClosed()
 {
     addPlaylist = null;
 }