public function isTransactionVerificationValid()
    {
        $this->verifyTransactionAtGateway();

        $result = $this->getResponse()['message'];

        switch ($result) {
            case self::VS:
                $validate = true;
                break;
            case self::ITF:
                $validate = false;
                break;
            default:
                $validate = false;
                break;
        }

        return $validate;
    }