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.activate(partA);
		assertEquals(partA, partService.getActivePart());
		partService.switchPerspective(perspectiveB);
		assertEquals(partB, partService.getActivePart());
		partService.activate(partB);
		assertEquals(partB, partService.getActivePart());
		partService.hidePart(partB);
		assertEquals(partC, partService.getActivePart());
	}
	/**
	 * Create two separate perspectives. The first one has three shared parts in
	 * it, partA, partB, and partC. The second perspective has partA by itself,
	 * partB obscured in a part stack by another part, partD, and then partC
	 * comes after the part stack.
	 * <p>
	 * partA is initially active, and we proceed to activate partC, partB, and
	 * then partA again. Now we switch to the second perspective where partA
	 * remains the active part. Hiding partA should cause partC to become the
	 * active part as partB is obscured by partD despite the fact that partB is
	 * the next available candidate in the activation history.
	 * </p>
	 */
	public void testHidePart_ActivationHistory23() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPart partA = BasicFactoryImpl.eINSTANCE.createPart();