def connectionLost(self, reason):
        """
        There is no longer a connection for this request to respond over.
        Clean up anything which can't be useful anymore.
        """
        self._disconnected = True
        self.channel = None
        if self.content is not None:
            self.content.close()
        for d in self.notifications:
            d.errback(reason)
        self.notifications = []

        There is no longer a connection for this request to respond over.
        Clean up anything which can't be useful anymore.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/http.py