anchor.diff:    List<String> get pathBlueprints => ['/wishlist/:wishlistId'];
   
     @override
  -  List<BeamPage> pagesBuilder(BuildContext context, BeamState state) => [
  +  List<BeamPage> pagesBuilder(BuildContext context, BeamState beamState) => [
           BeamPage(
             key: ValueKey('wishlist-${_appState.wishlists.length}'),
             child: WishlistListScreen(
  
positive.code:     return MaterialApp.router(
        title: 'Wishlist App',
        routerDelegate: BeamerRouterDelegate(
          locationBuilder: (state) => WishlistLocation(_appState, state),
        ),
        routeInformationParser: BeamerRouteInformationParser(),
      );
  
negative.code:             key: ValueKey('wishlist-${state.pathParameters['wishlistId']}'),
              child: WishlistScreen(
                wishlist: _appState.wishlists.firstWhere(
                  (wishlist) =>
                      wishlist.id == beamState.pathParameters['wishlistId'],
                  orElse: () {
                    final wishlist =
                        Wishlist(state.pathParameters['wishlistId']!);
  