JAXPStringXPathExpression exp = new JAXPStringXPathExpression();
exp.setXPath("java:org.apache.servicemix.expression.JAXPXPathExpressionTest.func(string(/header/value))");
DefaultNamespaceContext namespaceContext = new DefaultNamespaceContext();
namespaceContext.add("java", "http://xml.apache.org/xalan/java");
exp.setNamespaceContext(namespaceContext);
exp.setFunctionResolver(new XPathFunctionResolverImpl());
assertExpression(exp, "modified12", "<header><value>12</value></header>");
}