'Mute the volume.
Since we can\'t actually mute, we\'ll:
- On mute, store volume and set volume to 0
- On unmute, set volume to previously stored volume'

def mute_volume(self, mute):

    if (not (self.device and ('playback' in self._device_protocol_capabilities))):
        return
    self._volume_muted = mute
    if mute:
        self._previous_volume_level = self._volume_level
        self.set_volume_level(0)
    else:
        self.set_volume_level(self._previous_volume_level)
