def doStart(self):
        """
        Make sure startFactory is called.

        Users should not call this function themselves!
        """
        if not self.numPorts:
            if self.noisy:
                _loggerFor(self).info("Starting factory {factory!r}",
                                      factory=self)
            self.startFactory()
        self.numPorts = self.numPorts + 1

        Make sure startFactory is called.

        Users should not call this function themselves!
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/protocol.py