MusicController { public void next() { if (mediaController != null) { mediaController.getTransportControls().skipToNext(); } } MusicController(Flowable<Long> seconds, Rx rx); @Nullable Token getSessionToken(); PlaybackStateCompat getPlaybackState(); @Nullable String getCastName(); Flowable<Long> progress(); Flowable<Integer> state(); void play(); void pause(); void stop(); void playPause(); void playQueueItem(long id); void seekTo(long milliseconds); void next(); void previous(); void shuffle(); void repeat();  }
@Test public void next() { musicController.next(); verify(mockTransportControls, times(1)).skipToNext(); }