engine.compare(controlDoc, testDoc, listener);
engine.compare(controlDoc, testDoc, listener, null);
	private void listenToDifferences(String control, String test)		throws SAXException, IOException, ParserConfigurationException {		Document controlDoc = XMLUnit.buildControlDocument(control);		Document testDoc = XMLUnit.buildTestDocument(test);		engine.compare(controlDoc, testDoc, listener);	}