async def cleanup(self) -> None:
        """Causes on_cleanup signal

        Should be called after shutdown()
        """
        if self.on_cleanup.frozen:
            await self.on_cleanup.send(self)
        else:
            # If an exception occurs in startup, ensure cleanup contexts are completed.
            await self._cleanup_ctx._on_cleanup(self)
Causes on_cleanup signal

        Should be called after shutdown()
        
lib/aiohttp/web_app.py