public void PlaySongTest()
        {
            var playControlViewModel = new PlayControlViewModel();

            playControlViewModel.mediaPlayer.Open(null);
            Assert.AreEqual("00:00", playControlViewModel.ElapsedTimeMP3);
            playControlViewModel.PlaySong();
            Assert.IsNull(playControlViewModel.mediaPlayer.Source);
            playControlViewModel.mediaPlayer.Open(new Uri(path));
            playControlViewModel.PlaySong();
            Assert.IsNotNull(playControlViewModel.mediaPlayer.Source);
            Assert.IsFalse(playControlViewModel.IsStop);
            playControlViewModel.mediaPlayer.Stop();
        }