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
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);
		MPerspective perspective = AdvancedFactoryImpl.eINSTANCE
				.createPerspective();
		perspectiveStack.getChildren().add(perspective);
		perspectiveStack.setSelectedElement(perspective);
		MPartStack stackA = BasicFactoryImpl.eINSTANCE.createPartStack();
		perspective.getChildren().add(stackA);
		perspective.setSelectedElement(stackA);
		MPlaceholder placeholderA = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderA.setRef(partA);
		partA.setCurSharedRef(placeholderA);
		stackA.getChildren().add(placeholderA);
		stackA.setSelectedElement(placeholderA);
		MPartStack stackB = BasicFactoryImpl.eINSTANCE.createPartStack();
		perspective.getChildren().add(stackB);