code: async def _async_start(self, auto_register=True):
          
  
          if auto_register:
              await self._async_register()
          self.client = aioxmpp.PresenceManagedClient(self.jid,
                                                      aioxmpp.make_security_layer(self.password,
                                                                                  no_verify=not self.verify_security),
                                                      loop=self.loop,
                                                      logger=logging.getLogger(self.jid.localpart))
  
          # obtain an instance of the service
          self.message_dispatcher = self.client.summon(SimpleMessageDispatcher)
  
          # Presence service
          self.presence = PresenceManager(self)
  
          await self._async_connect()
  
          # register a message callback here
          self.message_dispatcher.register_callback(
              aioxmpp.MessageType.CHAT,
              None,
              self._message_received,
          )
          await self.setup()
          self._alive.set()
          for behaviour in self.behaviours:
              if not behaviour.is_running:
                  behaviour.start()
docs: Starts the agent from a coroutine. This fires some actions:
  
              * if auto_register: register the agent in the server
              * runs the event loop
              * connects the agent to the server
              * runs the registered behaviours
  
          Args:
            auto_register (bool, optional): register the agent in the server (Default value = True)