/**
  * Load the config handlers from the given config file.
  * Existing handlers will not be overwritten.
  * 
  * @param      string The path to a config_handlers.xml file.
  * 
  * @author     Felix Gilcher <*****@*****.**>
  * @since      1.0.0
  */
 protected static function loadConfigHandlersFile($cfg)
 {
     self::$handlers = (array) self::$handlers + (include AgaviConfigCache::checkConfig($cfg));
 }