Omnipay\Alipay\Requests\LegacyVerifyAppPayReturnRequest::validateParams PHP Метод

    public function validateParams()
    {
        $this->validate('result');
        $result = $this->getResult();
        if (!is_string($result)) {
            throw new InvalidRequestException('The result should be string');
        }
        parse_str($result, $data);
        if (!isset($data['sign'])) {
            throw new InvalidRequestException('The `result` is invalid');
        }
        if (!isset($data['sign_type'])) {
            throw new InvalidRequestException('The `result` is invalid');
        }
    }