public YouTubeDownloader(IMusicEncoderService encoder)
 {
     client       = new YoutubeClient();
     this.encoder = encoder;
 }
            internal static async Task <VideoInfo> CreateVideoInfo(YoutubeClient client, IMusicEncoderService encoder, string videoId)
            {
                var info = new VideoInfo()
                {
                    client  = client,
                    encoder = encoder,
                    videoId = videoId
                };
                await info.GetMetadata();

                return(info);
            }