client._on_connect exception rc type error about aiomqtt HOT 2 CLOSED

    def on_connect(self, func):
        """ Define the connect callback implementation.
        Expected signature for MQTT v3.1 and v3.1.1 is:
            connect_callback(client, userdata, flags, rc, properties=None)
        and for MQTT v5.0:
            connect_callback(client, userdata, flags, reasonCode, properties)
        client:     the client instance for this callback
        userdata:   the private user data as set in Client() or userdata_set()
        flags:      response flags sent by the broker
        rc:         the connection result
        reasonCode: the MQTT v5.0 reason code: an instance of the ReasonCode class.
                    ReasonCode may be compared to interger.