def makeSession(self):
        """
        Generate a new Session instance, and store it for future reference.
        """
        uid = self._mkuid()
        session = self.sessions[uid] = self.sessionFactory(self, uid)
        session.startCheckingExpiration()
        return session

        Generate a new Session instance, and store it for future reference.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/server.py