code: public int asNode(XPathContext xctxt)
            throws javax.xml.transform.TransformerException
    {
    	DTMIterator iter = execute(xctxt).iter();
      return iter.nextNode();
    }
docs: Return the first node out of the nodeset, if this expression is
  a nodeset expression.
  @param xctxt The XPath runtime context.
  @return the first node out of the nodeset, or DTM.NULL.
  
  @throws javax.xml.transform.TransformerException