Bug 334644 Cannot manually un/render a window that's directly under the application
Setting the 'toBeRendered' flag for a window that's a direct child of an application does nothing. The workaround is to manually de/construct it via the IPresentationEngine.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java
.get(IPresentationEngine.class.getName());
		renderer.removeGui(part);
		renderer.removeGui(window);
		while (Display.getCurrent().readAndDispatch()) {
			
		}
	}
	public void testAddWindowBug299219() throws Exception {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		application.setContext(appContext);
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		appContext.set(MApplication.class.getName(), application);
		wb = new E4Workbench(application, appContext);
		wb.createAndRunUI(window);
		assertNotNull(window.getWidget());
		MWindow window2 = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window2);
		assertNotNull(window2.getWidget());
	}
	public void testPartStack_SetActiveChildBug299379() throws Exception {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		application.setContext(appContext);
		appContext.set(MApplication.class.getName(), application);
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		MPartStack stack = BasicFactoryImpl.eINSTANCE.createPartStack();
		window.getChildren().add(stack);