Turn off the alsa_sink sink.

        This disconnects the sink from the relevant session events.

def off(self):
        """Turn off the alsa_sink sink.

        This disconnects the sink from the relevant session events.
        """
        spotifyconnect._session_instance.player.off(
            spotifyconnect.PlayerEvent.MUSIC_DELIVERY, self._on_music_delivery)
        assert spotifyconnect._session_instance.player.num_listeners(
            spotifyconnect.PlayerEvent.MUSIC_DELIVERY) == 0
        self._close()