Bug 303218 Active part no longer seems to be queryable from the application's context
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
MApplication application = MApplicationFactory.eINSTANCE
				.createApplication();
		MWindow window = MApplicationFactory.eINSTANCE.createWindow();
		application.getChildren().add(window);
		MPart saveablePart = MApplicationFactory.eINSTANCE.createPart();
		saveablePart.setDirty(before);
		window.getChildren().add(saveablePart);
		
		initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		Collection<MPart> dirtyParts = partService.getDirtyParts();
		assertNotNull(dirtyParts);
		if (before) {
			assertEquals(1, dirtyParts.size());
			assertEquals(saveablePart, dirtyParts.iterator().next());
		} else {
			assertEquals(0, dirtyParts.size());
		}
		saveablePart.setDirty(after);
		dirtyParts = partService.getDirtyParts();
		if (after) {
			assertEquals(1, dirtyParts.size());
			assertEquals(saveablePart, dirtyParts.iterator().next());
		} else {
			assertEquals(0, dirtyParts.size());
		}
	}
	public void testGetDirtyParts3_TrueTrue() {