Bug 322368 Sole part in a part stack shown by EPS should be set as the selected element
SSIA
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		MPlaceholder placeholder = partService.createSharedPart("partId",
				window, 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));
	}
	public void testHidePart_PartInAnotherWindow() {
		MApplication application = createApplication(
				new String[] { "partInWindow1" },
				new String[] { "partInWindow2" });
		MWindow window1 = application.getChildren().get(0);
		MWindow window2 = application.getChildren().get(1);
		getEngine().createGui(window1);
		getEngine().createGui(window2);
		EPartService partService1 = (EPartService) window1.getContext().get(
				EPartService.class.getName());
		EPartService partService2 = (EPartService) window2.getContext().get(
				EPartService.class.getName());
		MPart part1 = partService1.findPart("partInWindow1");
		MPart part2 = partService2.findPart("partInWindow2");
		assertTrue(part1.isToBeRendered());
		assertTrue(part2.isToBeRendered());
		partService1.hidePart(part2);
		assertTrue(part1.isToBeRendered());
		assertTrue(part2.isToBeRendered());