def listen(self, protocolFactory):
        """
        Implement L{IStreamServerEndpoint.listen} to listen for SSL on a
        TCP socket.
        """
        return defer.execute(self._reactor.listenSSL, self._port,
                             protocolFactory,
                             contextFactory=self._sslContextFactory,
                             backlog=self._backlog,
                             interface=self._interface)

        Implement L{IStreamServerEndpoint.listen} to listen for SSL on a
        TCP socket.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/endpoints.py