webview flutter avoid reloading
class ListWidget extends StatefulWidget {
  @override
  _ListWidgetState createState() => _ListWidgetState();
}
class _ListWidgetState extends State<ListWidget> with 
                  AutomaticKeepAliveClientMixin<ListWidget>{ // ** here
  @override
  Widget build(BuildContext context) {
    return Container();
  }
  @override
  bool get wantKeepAlive => true; // ** and here
}
