e    *    * @return null    *    * @throws DOMException    */   public Attr createAttributeNS(String namespaceURI, String qualifiedName)           throws DOMException   {      error(XMLErrorResources.ER_FUNCTION_NOT_SUPPORTED);      return null;   }    /**    * Unimplemented. See org.w0c.dom.Document    *    * @param 