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
private IEclipseContext applicationContext;
	private IPresentationEngine engine;
	@Override
	protected void setUp() throws Exception {
		applicationContext = E4Application.createDefaultContext();
		super.setUp();
	}
	protected String getEngineURI() {
		return "platform:/plugin/org.eclipse.e4.ui.tests/org.eclipse.e4.ui.tests.application.HeadlessContextPresentationEngine"; 
	}
	@Override
	protected void tearDown() throws Exception {
		super.tearDown();
		if (applicationContext instanceof IDisposable) {
			((IDisposable) applicationContext).dispose();
		}
	}
	private IPresentationEngine getEngine() {
		if (engine == null) {
			IContributionFactory contributionFactory = (IContributionFactory) applicationContext
					.get(IContributionFactory.class.getName());
			Object newEngine = contributionFactory.create(getEngineURI(),
					applicationContext);
			assertTrue(newEngine instanceof IPresentationEngine);
			applicationContext.set(IPresentationEngine.class.getName(),
					newEngine);
			engine = (IPresentationEngine) newEngine;
		}