Bug 343003 Selection changes for shared parts may not be propagated if they were not originally rendered in the model
The search algorithm currently only iterates through containers for parts. This will not work for parts that are represented by placeholders.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/ESelectionServiceTest.java
ESelectionService selectionServiceB = partContextB
				.get(ESelectionService.class);
		InjectPart injectPart = ContextInjectionFactory.make(InjectPart.class,
				partContextA);
		assertNull(injectPart.selection);
		Object o = new Target("");
		selectionServiceA.setSelection(o);
		assertEquals(o, injectPart.selection);
		partService.activate(partB);
		assertEquals("Part B doesn't post a selection, no change", o,
				injectPart.selection);
		partService.activate(partA);
		assertEquals(o, injectPart.selection);
		Object o2 = new Target("");
		selectionServiceB.setSelection(o2);
		assertEquals(o, injectPart.selection);
		partService.activate(partB);
		assertEquals(o2, injectPart.selection);
		partService.activate(partA);
		assertEquals(o, injectPart.selection);
	}
	private void initialize(IEclipseContext applicationContext,
			MApplication application) {
		applicationContext.set(MApplication.class.getName(), application);
		application.setContext(applicationContext);
		E4Workbench.processHierarchy(application);
		((Notifier) application).eAdapters().add(
				new UIEventPublisher(applicationContext));
	}
	static class SelectionListener implements ISelectionListener {