anchor.diff:                children: <Widget>[
                   new Expanded(
                     child: new Center(
  -                    child: new FlutterLogo(size: 100.0),
  +                    child: const FlutterLogo(size: 100.0),
                     ),
                   ),
                   new Expanded(
  
positive.code:                       List<Widget> children = <Widget>[];
                        children.add(new Text(
                          message,
                          style: new TextStyle(fontSize: 24.0),
                          textAlign: TextAlign.center
                        ));
                        if (progressMax >= 0.0) {
                          children.add(new SizedBox(height: 18.0));
                          children.add(new Center(child: new CircularProgressIndicator(value: progressMax > 0 ? progress / progressMax : null)));
                        }
                        return new Block(children: children);
  
negative.code:                 ),
                  new Expanded(
                    child: new Block(
                      padding: const EdgeInsets.symmetric(horizontal: 24.0),
                      children: <Widget>[ new Text(explanation, textAlign: TextAlign.center) ]
                    ),
                  ),
  