public function evaluate($values)
 {
     $value = $this->getParameter(1)->evaluate($values);
     if (is_numeric($value)) {
         return -$value;
     } else {
         return parent::evaluate($values);
     }
 }
 /**
  * @return OrderBy
  **/
 public function evaluate($values)
 {
     return parent::evaluate($values)->setDirection($this->direction);
 }