final XPathHelper xpathHelper = getContext().getXPathHelper();
final String result = xpathHelper.stringValueOf(currentResponse, getXpath());
// seems that result is "" and not null when nothing is found
if (result == null
|| (result.length() == 0 && xpathHelper.selectFirst(currentResponse, getXpath()) == null)) {
if (getDefault() == null)
{
throw new StepFailedException("No match for xpath expression <" + fXpath + ">", this);
}