def connectionLost(self, reason):
        """
        Called when the transport connection is lost.

        Informs all outstanding response handlers that the connection has been
        lost, and cleans up all internal state.
        """
        self._stillProducing = False
        self.setTimeout(None)

        for stream in self.streams.values():
            stream.connectionLost(reason)

        for streamID in list(self.streams.keys()):
            self._requestDone(streamID)

        # If we were going to force-close the transport, we don't have to now.
        if self._abortingCall is not None:
            self._abortingCall.cancel()
            self._abortingCall = None

        Called when the transport connection is lost.

        Informs all outstanding response handlers that the connection has been
        lost, and cleans up all internal state.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/_http2.py