static void destroyWindow(final Window window, final boolean last) {
   if (null == window) {
     return;
   }
   final Screen screen = window.getScreen();
   final Display display = screen.getDisplay();
   window.destroy();
   // System.err.println("************* Destroyed: "+window);
   if (last) {
     Assert.assertEquals(false, screen.isNativeValid());
     Assert.assertEquals(false, display.isNativeValid());
   } else {
     Assert.assertEquals(true, screen.isNativeValid());
     Assert.assertEquals(true, display.isNativeValid());
   }
   Assert.assertEquals(false, window.isNativeValid());
   Assert.assertEquals(false, window.isVisible());
 }