public boolean PlaylistHasItem(string playlistId,Guid itemID)
        {
            var playlist = _libraryManager.GetItemById(playlistId) as Playlist;

            if (playlist == null)
            {
                throw new ArgumentException("No Playlist exists with the supplied Id");
            }

            var playlistItems = playlist.LinkedChildren.ToList();

            foreach (var item in playlistItems)
            {
                if (item.id == itemID)
                {
                    return true;
                }
            }

            return false;
        }