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
window.getChildren().add(partStack);
		window.setSelectedElement(partStack);
		MPart part1 = BasicFactoryImpl.eINSTANCE.createPart();
		partStack.getChildren().add(part1);
		partStack.setSelectedElement(part1);
		MPart part2 = BasicFactoryImpl.eINSTANCE.createPart();
		partStack.getChildren().add(part2);
		application.setContext(appContext);
		appContext.set(MApplication.class.getName(), application);
		wb = new E4Workbench(application, appContext);
		wb.createAndRunUI(window);
		assertEquals(part1, partStack.getSelectedElement());
		appContext.get(IPresentationEngine.class).removeGui(window);
		assertEquals(part1, partStack.getSelectedElement());
	}
	public void testBug328629() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPartSashContainer partSashContainer = BasicFactoryImpl.eINSTANCE
				.createPartSashContainer();
		partSashContainer.setToBeRendered(false);
		window.getChildren().add(partSashContainer);
		application.setContext(appContext);
		appContext.set(MApplication.class.getName(), application);
		wb = new E4Workbench(application, appContext);
		wb.createAndRunUI(window);
		partSashContainer.setToBeRendered(true);