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
if (multipleAllowed) {
			assertEquals(createdPart, shownPart);
		} else {
			assertEquals(part, shownPart);
		}
	}
	public void testShowPart_Part_MultipleExists_TrueACTIVATE() {
		testShowPart_Part_MultipleExists(true, PartState.ACTIVATE);
	}
	public void testShowPart_Part_MultipleExists_FalseACTIVATE() {
		testShowPart_Part_MultipleExists(false, PartState.ACTIVATE);
	}
	public void testShowPart_Part_MultipleExists_TrueVISIBLE() {
		testShowPart_Part_MultipleExists(true, PartState.VISIBLE);
	}
	public void testShowPart_Part_MultipleExists_FalseVISIBLE() {
		testShowPart_Part_MultipleExists(false, PartState.VISIBLE);
	}
	public void testShowPart_Part_MultipleExists_TrueCREATE() {
		testShowPart_Part_MultipleExists(true, PartState.CREATE);
	}
	public void testShowPart_Part_MultipleExists_FalseCREATE() {
		testShowPart_Part_MultipleExists(false, PartState.CREATE);
	}
	private void testShowPart_Part_MultipleNonexistent(boolean multipleAllowed,
			PartState partState) {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);