/// <summary>
        /// プレイリストアイテムの一覧を更新する
        /// </summary>
        /// <param name="itemViewModel"></param>
        /// <returns></returns>
        private async Task UpdatePlaylistItemList(Playlist?playlist)
        {
            PlaylistItemList.Clear();
            Playlist.Value = playlist;
            if (playlist == null)
            {
                return;
            }

            Title.Value       = playlist.Title;
            Description.Value = playlist.Description;

            var playlistItems = await m_YouTubeService.GetPlaylistItems(playlist.PlaylistId);

            foreach (var item in playlistItems)
            {
                PlaylistItemList.Add(new PlaylistItemViewModel(item, m_WebClientService));
            }
        }