anchor.diff:    _BooksScreenState createState() => _BooksScreenState();
   }
   
  -class _BooksScreenState extends State<BooksScreen> with SingleTickerProviderStateMixin {
  +class _BooksScreenState extends State<BooksScreen>
  +    with SingleTickerProviderStateMixin {
     late final TabController _tabController;
   
     @override
     void initState() {
  -    _tabController =
  -        TabController(length: 2, vsync: this, initialIndex: widget.initialSelectedTab);
  +    _tabController = TabController(
  +        length: 2, vsync: this, initialIndex: widget.initialSelectedTab);
       super.initState();
     }
   
  
positive.code:               key: ValueKey('books'),
                widget: Builder(
                  builder: (context) => BooksScreen(
                    initialSelectedTab: context.vRouter.url!.contains('/new') ? 0 : 1,
                  ),
                ),
                buildTransition: (animation, _, child) =>
  
negative.code:   @override
    Widget build(BuildContext context) {
      return VWidgetGuard(
        beforeUpdate: (vRedirector) async => _tabController
            .animateTo(vRedirector.newVRouterData!.url!.contains('/new') ? 0 : 1),
        child: Column(
          children: [
            TabBar(
  