Bug 338707 Reconciler chokes on elements under parents that have been removed from the model
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/reconciler/ModelReconcilerScenarioTest.java
ModelReconciler reconciler = createModelReconciler();
		reconciler.recordChanges(application);
		MPartStack stack2 = BasicFactoryImpl.eINSTANCE.createPartStack();
		window.getChildren().add(0, stack2);
		stack2.getChildren().add(part1);
		Object state = reconciler.serialize();
		application = createApplication();
		window = application.getChildren().get(0);
		stack1 = (MPartStack) window.getChildren().get(0);
		part1 = (MPart) stack1.getChildren().get(0);
		part2 = (MPart) stack1.getChildren().get(1);
		Collection<ModelDelta> deltas = constructDeltas(application, state);
		assertEquals(2, stack1.getChildren().size());
		assertEquals(part1, stack1.getChildren().get(0));
		assertEquals(part2, stack1.getChildren().get(1));
		applyAll(deltas);
		assertEquals(1, stack1.getChildren().size());
		assertEquals(part2, stack1.getChildren().get(0));
		assertEquals(2, window.getChildren().size());
		stack2 = (MPartStack) window.getChildren().get(0);
		assertEquals(part1, stack2.getChildren().get(0));
	}
	/**
	 * <ol>
	 * <li>The application has a window with a stack that houses two parts, A
	 * and B.</li>
	 * <li>The user creates a new stack to the right of the original stack and
	 * places part A in it.</li>
	 * </ol>
	 */