Bug 327964 EPartService's hidePart may fail when trying to hide a shared part that's in a shared container
The placeholder retrieval code in the EPartService implementation doesn't go far down deep enough and actually stops at the shared container level. This causes the placeholder of the shared part to not be found.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
}
	public void testHidePart_Tagged_True() {
		testHidePart_Tagged(true);
	}
	public void testHidePart_Tagged_False() {
		testHidePart_Tagged(false);
	}
	public void testGetDirtyParts() {
		MApplication application = createApplication(1, new String[1][0]);
		MWindow window = application.getChildren().get(0);
		getEngine().createGui(window);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		Collection<MPart> dirtyParts = partService.getDirtyParts();
		assertNotNull(dirtyParts);
		assertEquals(0, dirtyParts.size());
	}
	public void testGetDirtyParts2() {
		MApplication application = createApplication("partId");
		MWindow window = application.getChildren().get(0);
		getEngine().createGui(window);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		Collection<MPart> dirtyParts = partService.getDirtyParts();
		assertNotNull(dirtyParts);
		assertEquals(0, dirtyParts.size());
	}
	private void testGetDirtyParts3(boolean before, boolean after) {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();