Bug 328946 Part activation history may return incorrect candidate if no placeholders could be found in a perspective
1. Window > Open Perspective > Other... > CVS Repository Exploring 2. Hide the 'CVS Repositories' view. 3. The 'History' view should become active, it is not.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		
		partStack.getChildren().remove(partA);
		
		partService.showPart(partB, partState);
		assertEquals(partB, partStack.getSelectedElement());
	}
	public void testShowPart_Bug328078_CREATE() {
		testShowPart_Bug328078(PartState.CREATE);
	}
	public void testShowPart_Bug328078_VISIBLE() {
		testShowPart_Bug328078(PartState.VISIBLE);
	}
	public void testShowPart_Bug328078_ACTIVATE() {
		testShowPart_Bug328078(PartState.ACTIVATE);
	}
	private void testHidePart_Bug325148(boolean force) {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPart part = BasicFactoryImpl.eINSTANCE.createPart();
		part.setToBeRendered(false);
		part.setContributionURI("platform:/plugin/org.eclipse.e4.ui.tests/org.eclipse.e4.ui.tests.workbench.SampleView");
		window.getSharedElements().add(part);
		MPerspectiveStack perspectiveStack = AdvancedFactoryImpl.eINSTANCE
				.createPerspectiveStack();
		window.getChildren().add(perspectiveStack);