function findBySerialNumber($serialNumber)
 {
     if (($model = Depot::find()->where(['serial_number' => $serialNumber])->one()) !== null) {
         return $model;
     } else {
         return null;
     }
 }
 public function actionList($serial_number = null)
 {
     if ($serial_number != null) {
         if (($model = $this->depotService->findBySerialNumber($serial_number)) !== null) {
             return array_merge(RestfulHelper::successfulStatusEnvolop(), ['depots' => RestfulHelper::depotToJsonFormat($model)]);
         } else {
             throw new NotFoundHttpException();
         }
     }
     return array_merge(RestfulHelper::successfulStatusEnvolop(), ['depots' => RestfulHelper::depotsToJsonFormat(Depot::find()->all())]);
 }