anchor.diff:          bottom: new TabBar(
             controller: _controller,
             isScrollable: true,
  +          indicator: getIndicator(),
             tabs: _allPages.map((_Page page) {
               switch (_demoStyle) {
                 case TabsDemoStyle.iconsAndText:
  
positive.code: class ScrollableTabsDemoState extends State<ScrollableTabsDemo> with SingleTickerProviderStateMixin {
    TabController _controller;
    TabsDemoStyle _demoStyle = TabsDemoStyle.iconsAndText;
  
    @override
    void initState() {
  
negative.code:     });
    }
  
    ShapeDecoration getIndicator() {
      if (!_customIndicator)
        return null;
  
      switch(_demoStyle) {
        case TabsDemoStyle.iconsAndText:
          return new ShapeDecoration(
            shape: const RoundedRectangleBorder(
              borderRadius: const BorderRadius.all(const Radius.circular(4.0)),
              side: const BorderSide(
                color: Colors.white24,
                width: 2.0,
              ),
            ) + const RoundedRectangleBorder(
              borderRadius: const BorderRadius.all(const Radius.circular(4.0)),
              side: const BorderSide(
                color: Colors.transparent,
                width: 4.0,
              ),
            ),
          );
  
        case TabsDemoStyle.iconsOnly:
          return new ShapeDecoration(
            shape: const CircleBorder(
              side: const BorderSide(
                color: Colors.white24,
                width: 4.0,
              ),
            ) + const CircleBorder(
              side: const BorderSide(
                color: Colors.transparent,
                width: 4.0,
              ),
            ),
          );
  
        case TabsDemoStyle.textOnly:
          return new ShapeDecoration(
            shape: const StadiumBorder(
              side: const BorderSide(
                color: Colors.white24,
                width: 2.0,
              ),
            ) + const StadiumBorder(
              side: const BorderSide(
                color: Colors.transparent,
                width: 4.0,
              ),
            ),
          );
      }
      return null;
    }
  
    @override
    Widget build(BuildContext context) {
      final Color iconColor = Theme.of(context).accentColor;
  