private void AddToPlaylist(LibraryUserPlaylist playlist, BaseItem[] itemsToAdd)
 {
     _playlistManager.AddToPlaylist(playlist.InternalId,
                                    itemsToAdd.Select(x => x.InternalId).ToArray(), playlist.User);
 }
 private void RemoveFromPlaylist(LibraryUserPlaylist playlist, BaseItem[] itemsToRemove)
 {
     _playlistManager.RemoveFromPlaylist(playlist.InternalId,
                                         itemsToRemove.Select(x => x.ListItemEntryId).ToArray());
 }