public function actionDispute()
 {
     $user = $this->checkAccess("create");
     $class_id = (int) Yii::$app->request->post('class_id');
     $dispute_type = (int) Yii::$app->request->post('dispute_type');
     $dispute = \common\models\TransactionHistory::checkDispute($class_id, $user->user_id);
     $class = \common\models\Classes::findOne($class_id);
     if ($dispute && $class) {
         if ($class->class_etime + 60 * 60 * 24 < time()) {
             return ApiHelper::errorResponse('Time for dispute expired.');
         }
         $dispute->transaction_dispute_status = 'open';
         $dispute->transaction_dispute_time = time();
         $dispute->transaction_dispute_type = $dispute_type;
         $dispute->save();
         return ApiHelper::successResponse(true);
     }
     return ApiHelper::errorResponse('Incorrect Access.');
 }