public void ShowBorderTest()
 {
     // for code coverage
     UITester.Dispatcher.Invoke(() =>
     {
         var popup = TutorialDialog.ShowBorder(UITester.MainWindow, Colors.Red, new Thickness(3));
         Assert.IsInstanceOfType(popup, typeof(Popup));
         Assert.IsTrue(popup.IsOpen);
         popup.IsOpen = false;
     });
 }