code: public DocumentFragment rtree(XPathContext support)
    {
      DocumentFragment docFrag = null;
      int result = rtf();
  
      if (DTM.NULL == result)
      {
        DTM frag = support.createDocumentFragment();
  
        // %OPT%
        frag.appendTextChild(str());
  
        docFrag = (DocumentFragment)frag.getNode(frag.getDocument());
      }
      else
      {
        DTM frag = support.getDTM(result);
        docFrag = (DocumentFragment)frag.getNode(frag.getDocument());
      }
  
      return docFrag;
    }
docs: Cast result object to a result tree fragment.
  
  @param support XPath context to use for the conversion
  
  @return the objec as a result tree fragment.