public static async Task AsyncMain()
        {
            HttpClient httpClient = new HttpClient();

            // Initialize YoutubeClient
            YoutubeClient ytClient = new YoutubeClient(httpClient);

            // Get sond PlaylistRecommendation by video Id.
            YoutubePlaylist youtubePlaylist = await ytClient.GetPlaylistRecommendation("9CyMi-n36rg");

            Console.WriteLine(youtubePlaylist);
        }