def post_init(self, app: Application) -> None:
        """Post init stage.

        Not an abstract method for sake of backward compatibility,
        but if the router wants to be aware of the application
        it can override this.
        """
Post init stage.

        Not an abstract method for sake of backward compatibility,
        but if the router wants to be aware of the application
        it can override this.
        
lib/aiohttp/abc.py