self.user_middleware: list[Middleware] = (
            [] if middleware is None else list(middleware)
        )
        self.middleware_stack: Union[ASGIApp, None] = None
        self.setup()

    def build_middleware_stack(self) -> ASGIApp:
        # Duplicate/override from Starlette to add AsyncExitStackMiddleware
        # inside of ExceptionMiddleware, inside of custom user middlewares
        debug = self.debug