Bug 307747 EPartService doesn't render new parts
1. Have a part in a stack, it is the selected part. 2. Show another part in that stack using PartState.CREATE or PartState.VISIBLE. 3. The part should've been rendered. It is not.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
}
	public void testSaveAll_NoHandler_FFF() {
		testSaveAll_NoHandler(false, false, false);
	}
	public void testSwitchWindows() {
		
		MApplication application = MApplicationFactory.eINSTANCE
				.createApplication();
		MWindow window1 = MApplicationFactory.eINSTANCE.createWindow();
		MWindow window2 = MApplicationFactory.eINSTANCE.createWindow();
		application.getChildren().add(window1);
		application.getChildren().add(window2);
		application.setSelectedElement(window1);
		
		MPart part = MApplicationFactory.eINSTANCE.createPart();
		window1.getChildren().add(part);
		window1.setSelectedElement(part);
		
		initialize(applicationContext, application);
		
		getEngine().createGui(window1);
		getEngine().createGui(window2);
		EPartService windowService1 = (EPartService) window1.getContext().get(
				EPartService.class.getName());
		EPartService windowService2 = (EPartService) window2.getContext().get(
				EPartService.class.getName());
		assertNotNull(windowService1);
		assertNotNull(windowService2);
		assertNotNull("The first part is active in the first window",
				windowService1.getActivePart());