Bug 329310 Part service does not autogenerate stacks if the last container is not one
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
stackB.getChildren().add(placeholderPartB2);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(partB1);
		partService.activate(partB2);
		partService.hidePart(partB2);
		assertEquals(partB1, stackB.getSelectedElement());
		assertEquals(partB1, partService.getActivePart());
		partService.hidePart(partB1);
		assertNull(stackB.getSelectedElement());
		assertEquals(partA, partService.getActivePart());
	}
	public void testHidePart_ActivationHistory14() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPart partA = BasicFactoryImpl.eINSTANCE.createPart();
		window.getSharedElements().add(partA);
		MPart partB = BasicFactoryImpl.eINSTANCE.createPart();
		window.getSharedElements().add(partB);
		MPart partC = BasicFactoryImpl.eINSTANCE.createPart();
		window.getSharedElements().add(partC);
		MPerspectiveStack perspectiveStack = AdvancedFactoryImpl.eINSTANCE
				.createPerspectiveStack();
		window.getChildren().add(perspectiveStack);
		window.setSelectedElement(perspectiveStack);