/**
  * Add the query keys found in the configuration properties to the Dataset "keys" used bei the
  * cFIND method.
  *
  * @param cfg the configuration properties for this class.
  * @throws ParseException if a given properties for the keys was not found.
  */
 private void addQueryKeys(ConfigProperties cfg) throws ParseException {
   // Add/replace keys found in the configuration file. Syntax key.<element name> = <element value>
   for (Enumeration it = cfg.keys(); it.hasMoreElements(); ) {
     String key = (String) it.nextElement();
     if (key.startsWith("key.")) {
       try {
         keys.putXX(Tags.forName(key.substring(4)), cfg.getProperty(key));
       } catch (Exception e) {
         throw new ParseException(
             "Illegal entry in configuration filr: " + key + "=" + cfg.getProperty(key), 0);
       }
     }
   }
 }