code: public function sendFailResponse($data, $httpStatusCode = 500)
      {
          \Yii::$app->response->format = Response::FORMAT_JSON;
          \Yii::$app->response->setStatusCode($httpStatusCode, $this->httpStatuses->getReasonPhrase($httpStatusCode));
  
          return [
              'status' => 'fail',
              'data' => $data
          ];
      }
docs: Sends fail response
  @param $data
  @author Oluwarotimi Akintewe <akintewe.rotimi@gmail.com>
  @author Adegoke Obasa <goke@cottacush.com>
  @param int $httpStatusCode
  @return array