/**
  * @see rental/inc/model/rental_model#validates()
  */
 public function validates()
 {
     $valid = parent::validates();
     // Check that we have a correct agresso id
     /*
     if ($this->get_agresso_id() && !rental_validator::valid_agresso_id($this->get_agresso_id(), $this->validation_errors['agresso_id'])) {
     	$valid = false;
     }
     */
     return $valid;
 }