code: def establish_connection(self):
          
          conninfo = self.connection
          if not conninfo.port:
              conninfo.port = self.default_port
          credentials = pika.PlainCredentials(conninfo.userid,
                                              conninfo.password)
          return self._connection_cls(pika.ConnectionParameters(
                                             conninfo.hostname,
                                             port=conninfo.port,
                                             virtual_host=conninfo.virtual_host,
                                             credentials=credentials))
docs: Establish connection to the AMQP broker.