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
perspectiveB.setSelectedElement(partStackB);
		MPlaceholder placeholderC = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		partC.setCurSharedRef(placeholderC);
		placeholderC.setRef(partC);
		partStackB.getChildren().add(placeholderC);
		partStackB.setSelectedElement(placeholderC);
		MPlaceholder placeholderB2 = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderB2.setRef(partB);
		partStackB.getChildren().add(placeholderB2);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(partA);
		partService.switchPerspective(perspectiveB);
		partService.activate(partB);
		partService.switchPerspective(perspectiveA);
		assertEquals(partA, partService.getActivePart());
		partService.activate(partA);
		assertEquals(partA, partService.getActivePart());
		partService.switchPerspective(perspectiveB);
		assertEquals(partB, partService.getActivePart());
		partService.activate(partC);
		assertEquals(partC, partService.getActivePart());
		partService.switchPerspective(perspectiveA);
		assertEquals(partA, partService.getActivePart());
		partService.hidePart(partB, force);
		assertFalse(placeholderB1.isToBeRendered());
	}