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
"partFrontA", "partBackA" }, new String[] { "partFrontB",
				"partBackB" });
		MWindow windowA = application.getChildren().get(0);
		MPartStack partStackA = (MPartStack) windowA.getChildren().get(0);
		MPart partFrontA = (MPart) partStackA.getChildren().get(0);
		MPart partBackA = (MPart) partStackA.getChildren().get(1);
		partStackA.setSelectedElement(partFrontA);
		MWindow windowB = application.getChildren().get(1);
		MPartStack partStackB = (MPartStack) windowB.getChildren().get(0);
		MPart partFrontB = (MPart) partStackB.getChildren().get(0);
		MPart partBackB = (MPart) partStackB.getChildren().get(1);
		partStackB.setSelectedElement(partFrontB);
		getEngine().createGui(windowA);
		getEngine().createGui(windowB);
		EPartService partServiceA = (EPartService) partFrontA.getContext().get(
				EPartService.class.getName());
		EPartService partServiceB = (EPartService) partFrontB.getContext().get(
				EPartService.class.getName());
		partServiceA.activate(partBackA);
		assertEquals(windowA, application.getSelectedElement());
		IEclipseContext a = application.getContext().getActiveLeaf();
		MPart aPart = (MPart) a.get(MPart.class.getName());
		assertEquals(partBackA, aPart);
		partServiceB.activate(partBackB);
		assertEquals(windowB, application.getSelectedElement());
		a = application.getContext().getActiveLeaf();
		aPart = (MPart) a.get(MPart.class.getName());
		assertEquals(partBackB, aPart);
	}
	public void testActivate_partService_activePart() {