ElemExsltFunction elemFunc = getFunction(extFunction.getFunctionName());
if (null != elemFunc) {
XPathContext context = exprContext.getXPathContext();
TransformerImpl transformer = (TransformerImpl)context.getOwnerObject();
transformer.pushCurrentFuncResult(null);
elemFunc.execute(transformer, methodArgs);
XObject val = (XObject)transformer.popCurrentFuncResult();
return (val == null) ? new XString("") // value if no result element.