def __post_init__(self):
        """Initialize the app.

        Raises:
            ValueError: If the event namespace is not provided in the config.
                        Also, if there are multiple client subclasses of rx.BaseState(Subclasses of rx.BaseState should consist
                        of the DefaultState and the client app state).
        """
        # Special case to allow test cases have multiple subclasses of rx.BaseState.
        if not is_testing_env() and BaseState.__subclasses__() != [State]:
            # Only rx.State is allowed as Base State subclass.
            msg = "rx.BaseState cannot be subclassed directly. Use rx.State instead"
            raise ValueError(msg)

        get_config(reload=True)

        if "breakpoints" in self.style:
            set_breakpoints(self.style.pop("breakpoints"))

        # Set up the API.
        self._api = Starlette()
        App._add_cors(self._api)
        self._add_default_endpoints()

        for clz in App.__mro__:
            if clz == App:
                continue
            if issubclass(clz, AppMixin):
                clz._init_mixin(self)

        self._setup_state()

        # Set up the admin dash.
        self._setup_admin_dash()

        if sys.platform == "win32" and not is_prod_mode():
            # Hack to fix Windows hot reload issue.
            from reflex.utils.compat import windows_hot_reload_lifespan_hack

            self.register_lifespan_task(windows_hot_reload_lifespan_hack)
Initialize the app.

        Raises:
            ValueError: If the event namespace is not provided in the config.
                        Also, if there are multiple client subclasses of rx.BaseState(Subclasses of rx.BaseState should consist
                        of the DefaultState and the client app state).
        
reflex/app.py