anchor.diff:        scrollableKey: _scrollableKey,
         appBarBehavior: AppBarBehavior.scroll,
         appBar: new AppBar(
  +        heroTag: _disableHeroTransition,
           expandedHeight: _getAppBarHeight(context),
           backgroundColor: Colors.transparent,
           elevation: 0,
  
positive.code:   final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();
    final GlobalKey<ScrollableState> _scrollableKey = new GlobalKey<ScrollableState>();
    final TextStyle menuItemStyle = new PestoStyle(fontSize: 15.0, color: Colors.black54, height: 24.0/15.0);
  
    double _getAppBarHeight(BuildContext context) => MediaQuery.of(context).size.height * 0.3;
  
  
negative.code:             ]
            )
          ],
        ),
        body: _buildContainer(context)
      );
  