code: public static Node asNode(String nodeName, Node node)
              throws XPathExpressionException {
          return asNode(nodeName, node, xpath());
      }
docs: Evaluates the specified XPath expression and returns the result as a
  Node.
  
  @param nodeName
  The XPath expression to evaluate.
  @param node
  The node to run the expression on.
  
  @return The Node result.
  
  @throws XPathExpressionException
  If there was a problem processing the specified XPath
  expression.