Document inDocument = XMLUnit.buildControlDocument(inXMLString); assertXpathExists(xPathExpression, inDocument);
assertXpathExists(xPathExpression, inXMLString, null);
    public static void assertXpathExists(String xPathExpression,     String inXMLString)         throws IOException, SAXException, XpathException {        Document inDocument = XMLUnit.buildControlDocument(inXMLString);        assertXpathExists(xPathExpression, inDocument);    }