def close(self) -> None:
        """Close connection.

        Stop accepting new pipelining messages and close
        connection when handlers done processing messages.
        """
        self._close = True
        if self._waiter:
            self._waiter.cancel()
Close connection.

        Stop accepting new pipelining messages and close
        connection when handlers done processing messages.
        
lib/aiohttp/web_protocol.py