Bug 326300 EPartService's activate(MPart) method may not work if you activate the window's active part
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
MPlaceholder placeholder = partService.createSharedPart("partId", true);
		MPart sharedPart = (MPart) placeholder.getRef();
		sharedPart.setCurSharedRef(placeholder);
		partService.showPart(sharedPart, PartState.ACTIVATE);
		assertEquals(1, perspective.getChildren().size());
		assertEquals(placeholder, perspective.getChildren().get(0));
	}
	private void testShowPart_Bug322368_Part(PartState partState) {
		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);
		window.getChildren().add(part);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		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() {