code: def set_volume(self, volume=50):
          
          assert(volume in range(101))
  
          log.debug("setting volume...")
  
          cmd, url = DEVICE_URLS["set_volume"]
          json_data = {
              "volume": volume,
          }
          return self._exec(cmd, url, json_data=json_data)
docs: allows to change the volume
  
          :param int volume: volume to be set for the current device
                             [0..100] (default: 50)