protected function getValues($prefix, $category, $keys)
 {
     if ('enabled' == $category) {
         $this->enabled = $this->replaceConstants($keys);
     } else {
         if ('loggers' == $category) {
             $this->loggers = $this->replaceConstants($keys);
             return array();
         }
     }
     return parent::getValues($prefix, $category, $keys);
 }