class AfmPlayerView extends LinearLayout implements
        View.OnClickListener, SeekBar.OnSeekBarChangeListener {

    public List<AfmAudio> getMyPlaylist() {
        return afmAudioPlayer.getPlaylist();
    }

}

class AfmPlayerViewTest {

    @Mock Context context;
    private AfmPlayerView afmPlayerView;
    private List<AfmAudio> playlist;

    @Test
    public void player_has_same_size_of_playlist_user(){

        assertEquals(afmPlayerView.getMyPlaylist().size(), playlist.size());
    }

}