private void Interrupt_PlaylistEnded(object sender, EventArgs e)
 {
     // восстанавливаем Background
     interrupt.PlaylistEnded -= Interrupt_PlaylistEnded;
     interrupt = null;
     background.Continue();
 }
 public MediaController(IMediaEngine mediaEngine)
 {
     this.mediaEngine = mediaEngine;
     this.background  = new MediaPlaylist(mediaEngine, true);
     this.interrupt   = new MediaPlaylist(mediaEngine, false);
 }