code: def _send_tune_ok(self, frame_in):
          
          self.max_allowed_channels = self._negotiate(frame_in.channel_max,
                                                      MAX_CHANNELS)
          self.max_frame_size = self._negotiate(frame_in.frame_max,
                                                MAX_FRAME_SIZE)
          LOGGER.debug(
              'Negotiated max frame size %d, max channels %d',
              self.max_frame_size, self.max_allowed_channels
          )
  
          tune_ok_frame = specification.Connection.TuneOk(
              channel_max=self.max_allowed_channels,
              frame_max=self.max_frame_size,
              heartbeat=self._heartbeat)
          self._write_frame(tune_ok_frame)
docs: Send Tune OK frame.
  
          :param specification.Connection.Tune frame_in: Tune frame.
  
          :return: