}
  LiteralNode(Node source)  {    this.source = source;    if (source.getNodeType() == Node.ELEMENT_NODE)      {        NamedNodeMap attrs = source.getAttributes();        Node attr = attrs.getNamedItemNS(Stylesheet.XSL_NS,                                         "exclude-result-prefixes");        if (attr != null)          {            elementExcludeResultPrefixes = new HashSet();            StringTokenizer st = new StringTokenizer(attr.getNodeValue());            while (st.hasMoreTokens())              {                elementExcludeResultPrefixes.add(st.nextToken());              }          }        else          {            elementExcludeResultPrefixes = Collections.EMPTY_SET;          }      }    else      {        elementExcludeResultPrefixes = null;      }  }