def startService(self):
        """
        Start this L{ClientService}, initiating the connection retry loop.
        """
        if self.running:
            self._log.warn("Duplicate ClientService.startService {log_source}")
            return
        super(ClientService, self).startService()
        self._machine.start()

        Start this L{ClientService}, initiating the connection retry loop.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/application/internet.py