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
window.getSharedElements().add(part);
		MPerspectiveStack perspectiveStack = AdvancedFactoryImpl.eINSTANCE
				.createPerspectiveStack();
		window.getChildren().add(perspectiveStack);
		window.setSelectedElement(perspectiveStack);
		MPerspective perspectiveA = AdvancedFactoryImpl.eINSTANCE
				.createPerspective();
		perspectiveStack.getChildren().add(perspectiveA);
		perspectiveStack.setSelectedElement(perspectiveA);
		MPlaceholder placeholderA = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderA.setRef(part);
		part.setCurSharedRef(placeholderA);
		perspectiveA.getChildren().add(placeholderA);
		perspectiveA.setSelectedElement(placeholderA);
		MPerspective perspectiveB = AdvancedFactoryImpl.eINSTANCE
				.createPerspective();
		perspectiveStack.getChildren().add(perspectiveB);
		MPlaceholder placeholderB = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderB.setToBeRendered(false);
		placeholderB.setRef(part);
		perspectiveB.getChildren().add(placeholderB);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(part);
		assertNotNull(part.getContext());
		partService.switchPerspective(perspectiveB);
		assertNotNull(part.getContext());