anchor.diff:      String display = style.display;
       String visibility = style.visibility;
   
  -    return int.parse(opacity) > 0 && display != "none" && visibility != "visible";
  +    return int.parse(opacity) > 0 && display != "none" && visibility == "visible";
     }
   
     List<SparkDialogButton> get buttons =>
  
positive.code:     test('ensure about dialog open', () {
        ModalUITester modalTester = new ModalUITester("aboutDialog");
        expect(modalTester.functionallyOpened, true);
      });
  
      test('close dialog', () { // 10 26107
  
negative.code:       modalTester.clickButton("done");
        expect(modalTester.functionallyOpened, false);
  
        return new Future.delayed(const Duration(milliseconds: 1000)).then((_){
          expect(modalTester.visuallyOpened, false);
        });
      });
  