private void NextClicked(object sender, RoutedEventArgs e)
 {
     if (_player.Next())
     {
         _player.Play();
     }
 }
 public MainWindow()
 {
     InitializeComponent();
     _player = new PlayerBuilder()
               .SetWavePlayer(new WaveOutEvent())
               .AddTrack("A.mp3")
               .AddTrack("B.mp3")
               .Build();
     _player.Next();
 }