Bug 334559 EPartService's part searching path may not include parts outside of the active perspective
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
MPart partB2 = BasicFactoryImpl.eINSTANCE.createPart();
		stackB.getChildren().add(partB2);
		MPart partB3 = BasicFactoryImpl.eINSTANCE.createPart();
		stackB.getChildren().add(partB3);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(partB2);
		partService.activate(partB3);
		partService.activate(partA);
		partService.hidePart(partB3);
		assertEquals(partB2, stackB.getSelectedElement());
	}
	public void testHidePart_ActivationHistory02() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPartStack stackA = BasicFactoryImpl.eINSTANCE.createPartStack();
		window.getChildren().add(stackA);
		window.setSelectedElement(stackA);
		MPartStack stackB = BasicFactoryImpl.eINSTANCE.createPartStack();
		window.getChildren().add(stackB);
		MPart partA = BasicFactoryImpl.eINSTANCE.createPart();
		stackA.getChildren().add(partA);
		stackA.setSelectedElement(partA);
		MPart partB = BasicFactoryImpl.eINSTANCE.createPart();
		stackB.getChildren().add(partB);
		stackB.setSelectedElement(partB);