Bug 327765 EPartService will hide a part of another perspective
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
partC.setCurSharedRef(placeholderC1);
		perspectiveA.getChildren().add(placeholderC1);
		perspectiveA.setSelectedElement(placeholderC1);
		MPerspective perspectiveB = AdvancedFactoryImpl.eINSTANCE
				.createPerspective();
		perspectiveStack.getChildren().add(perspectiveB);
		MPlaceholder placeholderA2 = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderA2.setRef(partA);
		partA.setCurSharedRef(placeholderA2);
		perspectiveB.getChildren().add(placeholderA2);
		perspectiveB.setSelectedElement(placeholderA2);
		MPlaceholder placeholderB2 = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderB2.setRef(partB);
		partB.setCurSharedRef(placeholderB2);
		perspectiveB.getChildren().add(placeholderB2);
		MPlaceholder placeholderC2 = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderC2.setRef(partC);
		perspectiveB.getChildren().add(placeholderC2);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		assertEquals(placeholderC1, partC.getCurSharedRef());
		assertEquals(placeholderB2, partB.getCurSharedRef());
		assertEquals(placeholderA2, partA.getCurSharedRef());
		assertEquals(partC, placeholderC1.getRef());
		assertEquals(partA, placeholderA2.getRef());
		assertEquals(partB, placeholderB2.getRef());
		assertEquals(partC, placeholderC2.getRef());