anchor.diff:              return new Material(
                 child: new RaisedButton(
                   child: new Text('X'),
  -                onPressed: () { Navigator.of(context).pushNamed('/next'); }
  -              )
  +                onPressed: () { Navigator.of(context).pushNamed('/next'); },
  +              ),
               );
             }
           ),
  
positive.code:     await tester.pumpWidget(
        new MaterialApp(
          home: new MaterialApp(
            home: new Text('Home sweet home')
          )
        )
      );
  
      expect(find.text('Home sweet home'), findsOneWidget);
  
negative.code:               builder: (BuildContext context) {
                  ++buildCounter;
                  return new Container();
                },
              );
            },
          },
        ),
      );
  
      expect(buildCounter, 0);
  