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
EPartService partService = window.getContext().get(EPartService.class);
		partService.showPart(part, partState);
		assertNotNull(window.getSelectedElement());
		assertEquals(part, window.getSelectedElement());
	}
	public void testShowPart_Bug322368_Part_ACTIVATE() {
		testShowPart_Bug322368_Part(PartState.ACTIVATE);
	}
	public void testShowPart_Bug322368_Part_VISIBLE() {
		testShowPart_Bug322368_Part(PartState.VISIBLE);
	}
	public void testShowPart_Bug322368_Part_CREATE() {
		testShowPart_Bug322368_Part(PartState.CREATE);
	}
	private void testShowPart_Bug322368_Placeholder(PartState partState) {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MPartDescriptor partDescriptor = org.eclipse.e4.ui.model.application.descriptor.basic.impl.BasicFactoryImpl.eINSTANCE
				.createPartDescriptor();
		partDescriptor.setElementId("partId");
		partDescriptor.setAllowMultiple(true);
		application.getDescriptors().add(partDescriptor);
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPerspectiveStack perspectiveStack = AdvancedFactoryImpl.eINSTANCE
				.createPerspectiveStack();
		window.getChildren().add(perspectiveStack);
		window.setSelectedElement(perspectiveStack);
		MPerspective perspective = AdvancedFactoryImpl.eINSTANCE