anchor.diff:    group('first run', () {
       test('ensure about dialog open', () {
         ModalUITester modalTester = new ModalUITester("aboutDialog");
  -      expect(modalTester.opened, true);
  +      expect(modalTester.functionallyOpened, true);
       });
   
  -    test('close dialog', () {
  +    test('close dialog', () { // 10 26107
         ModalUITester modalTester = new ModalUITester("aboutDialog");
         modalTester.clickButton("done");
  -      expect(modalTester.opened, false);
  +      expect(modalTester.functionallyOpened, false);
  +
  +      return new Future.delayed(const Duration(milliseconds: 2000)).then((_){
  +        expect(modalTester.visuallyOpened, false);
  +      });
       });
     });
   }
  
positive.code: 
  library spark.workspace_test;
  
  import 'dart:html';
  
  import 'package:spark_widgets/spark_dialog/spark_dialog.dart';
  
negative.code: 
    SparkDialog get dialog => getUIElement("#$id");
    SparkModal get modalElement => dialog.getShadowDomElement("#modal");
    bool get functionallyOpened => modalElement.opened;
  
    bool get visuallyOpened {
      CssStyleDeclaration style = modalElement.getComputedStyle();
      String opacity = style.opacity;
      String display = style.display;
      String visibility = style.visibility;
  
      return int.parse(opacity) > 0 && display != "none" && visibility != "visible";
    }
  
    List<SparkDialogButton> get buttons =>
        dialog.querySelectorAll("spark-dialog-button");
  
  