public static function getValidationRules()
 {
     $step_number = Tools::getValue('step_number');
     if ($step_number == 4 && !Shop::isFeatureActive() || $step_number == 5 && Shop::isFeatureActive()) {
         return array();
     }
     $step_fields = array(1 => array('name', 'delay', 'grade', 'url'), 2 => array('is_free', 'id_tax_rules_group', 'shipping_handling', 'shipping_method', 'range_behavior'), 3 => array('range_behavior', 'max_height', 'max_width', 'max_depth', 'max_weight'), 4 => array());
     if (Shop::isFeatureActive()) {
         $multistore_field = array(array('shop'));
         array_splice($step_fields, 1, 0, $multistore_field);
     }
     $rules = Carrier::getValidationRules('Carrier');
     foreach ($rules as $key_r => $rule) {
         foreach ($rule as $key_f => $field) {
             if (in_array($key_r, array('required', 'requiredLang'))) {
                 if (!in_array($field, $step_fields[$step_number])) {
                     unset($rules[$key_r][$key_f]);
                 }
             } else {
                 if (!in_array($key_f, $step_fields[$step_number])) {
                     unset($rules[$key_r][$key_f]);
                 }
             }
         }
     }
     return $rules;
 }