Bug 303831 Warnings logged when trying to merge changes to an MPart's 'closeable' attribute
Warnings are printed out to syserr. --- WARNING: Unknown feature found, reconciliation may fail: Part#closeable
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/reconciler/ModelReconcilerPartTest.java
ModelReconciler reconciler = createModelReconciler();
		reconciler.recordChanges(application);
		MToolBar toolBar = MApplicationFactory.eINSTANCE.createToolBar();
		part.setToolbar(toolBar);
		Object state = reconciler.serialize();
		application = createApplication();
		window = application.getChildren().get(0);
		part = (MPart) window.getChildren().get(0);
		Collection<ModelDelta> deltas = constructDeltas(application, state);
		assertNull(part.getToolbar());
		applyAll(deltas);
		assertNotNull(part.getToolbar());
	}
	public void testPart_ToolBar_Unset() {
		MApplication application = createApplication();
		MWindow window = createWindow(application);
		MPart part = MApplicationFactory.eINSTANCE.createPart();
		window.getChildren().add(part);
		MToolBar toolBar = MApplicationFactory.eINSTANCE.createToolBar();
		part.setToolbar(toolBar);
		saveModel();
		ModelReconciler reconciler = createModelReconciler();
		reconciler.recordChanges(application);
		part.setToolbar(null);
		Object state = reconciler.serialize();
		application = createApplication();
		window = application.getChildren().get(0);
		part = (MPart) window.getChildren().get(0);
		toolBar = MApplicationFactory.eINSTANCE.createToolBar();
		part.setToolbar(toolBar);