docs: def connect(self):
          """
          connect
          """
          _logger.debug("Start connecting to broker")
          while True:
              try:
                  self.client.connect(self.broker_host, self.broker_port,
                                      self.broker_keepalive)
                  break
              except Exception:
                  _logger.debug(
                      "Connect failed. wait %s sec" % self.connect_delay)
                  sleep(self.connect_delay)
  
          self.client.loop_forever()