def set_volume(self, instance_id=0, channel='Master', desired_volume=0):
    action = self.service.get_action('SetVolume')
    return action.call(InstanceID=instance_id, Channel=channel, DesiredVolume=desired_volume)
def set_volume(self, instance_id=0, channel='Master', desired_volume=0):
    action = self.service.get_action('SetVolume')
    return action.call(InstanceID=instance_id, Channel=channel, DesiredVolume=desired_volume)