code: def _SendMessages(self, grr_msgs, background=False):
      
      message_list = rdf_flows.PackedMessageList()
      communicator.Communicator.EncodeMessageList(
          rdf_flows.MessageList(job=grr_msgs), message_list)
      fs_msg = fs_common_pb2.Message(
          message_type="MessageList",
          destination=fs_common_pb2.Address(service_name="GRR"),
          background=background)
      fs_msg.data.Pack(message_list.AsPrimitiveProto())
  
      try:
        sent_bytes = self._fs.Send(fs_msg)
      except (IOError, struct.error):
        logging.critical("Broken local Fleetspeak connection (write end).")
        raise
  
      stats_collector_instance.Get().IncrementCounter("grr_client_sent_bytes",
                                                      sent_bytes)
docs: Sends a block of messages through Fleetspeak.