anchor.diff:  
   import 'package:spark_widgets/spark_dialog/spark_dialog.dart';
   import 'package:spark_widgets/spark_dialog_button/spark_dialog_button.dart';
  +import 'package:spark_widgets/spark_menu_button/spark_menu_button.dart';
  +import 'package:spark_widgets/spark_menu_item/spark_menu_item.dart';
   import 'package:spark_widgets/spark_button/spark_button.dart';
   import 'package:spark_widgets/spark_modal/spark_modal.dart';
   import 'package:unittest/unittest.dart';
  
positive.code:     throw "Could not find button with title $title";
    }
  
    void clickButton(String title) {
      SparkDialogButton button = getButton(title);
      Rectangle<int> bounds = button.getBoundingClientRect();
      button.dispatchEvent(new MouseEvent("click",
          clientX: bounds.left.toInt() + 1, clientY:bounds.top.toInt() + 1));
    }
  }
  
  defineTests() {
  
negative.code: class UITester {
    SparkPolymerUI get ui => document.querySelector('#topUi');
    Element getUIElement(String selectors) => ui.getShadowDomElement(selectors);
    void sendMouseEvent(Element element, String eventType) {
      Rectangle<int> bounds = element.getBoundingClientRect();
      element.dispatchEvent(new MouseEvent(eventType,
          clientX: bounds.left.toInt() + bounds.width ~/ 2,
          clientY:bounds.top.toInt() + bounds.height ~/ 2));
    }
  
    void clickElement(Element element) {
      sendMouseEvent(element, "mouseover");
      sendMouseEvent(element, "click");
    }
  }
  
  class SparkUITester extends UITester {
    SparkMenuButton get menu => getUIElement("#mainMenu");
    SparkButton get menuButton => getUIElement("#mainMenu > spark-button");
    void selectMenu() => menuButton.click();
    List<SparkMenuItem> get menuItems => menu.querySelectorAll("spark-menu-item");
    SparkMenuItem getMenuItem(String id) {
        return menuItems.firstWhere((SparkMenuItem item) =>
            item.attributes["action-id"] == id);
    }
    SparkMenuItem get newProjectMenu => getMenuItem("project-new");
    void selectNewProject() {
      SparkMenuItem item = newProjectMenu;
      clickElement(item);
    }
  }
  
  