code: def set_volume(self, volume):
          
          if volume < -80 or volume > 18:
              raise ValueError("Invalid volume")
  
          try:
              return bool(self.send_get_command(
                  self._urls.command_set_volume % volume))
          except requests.exceptions.RequestException:
              _LOGGER.error("Connection error: set volume command not sent.")
              return False
docs: Set receiver volume via HTTP get command.
  
          Volume is send in a format like -50.0.
          Minimum is -80.0, maximum at 18.0