public async Task ChooseBestVideo()
{
IEnumerable <VideoInfo> videoInfos = await DownloadUrlResolver.GetDownloadUrlsAsync("https://www.youtube.com/watch?v=vxMxYgkUcdU");
var downloader = new AudioDownloader();
Assert.IsNotNull(downloader.ChooseBest(videoInfos));
Assert.IsTrue(downloader.ChooseBest(videoInfos).CanExtractAudio);
}