anchor.diff:      } else if (path is LoginRoutePath) {
         // Log out
         _appState.viewingBooks = false;
  -      _appState.isLoggedIn = false;
  +      _appState.auth.signOut();
       }
     }
   
  
positive.code: 
    @override
    AppRoutePath get currentConfiguration {
      if (!_appState.isLoggedIn) {
        return LoginRoutePath();
      } else if (_appState.viewingBooks) {
        return BooksRoutePath();
  
negative.code:     with ChangeNotifier, PopNavigatorRouterDelegateMixin<AppRoutePath> {
    @override
    final GlobalKey<NavigatorState> navigatorKey;
    final AppState _appState = AppState(MockAuthentication());
  
    BookRouterDelegate() : navigatorKey = GlobalKey<NavigatorState>() {
      _appState.addListener(() => notifyListeners());
  