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

    public function validateParams()
    {
        if (empty($this->params->all())) {
            throw new InvalidRequestException('The `params` or $_REQUEST is empty');
        }
        if (!$this->params->has('sign_type')) {
            throw new InvalidRequestException('The sign_type is required');
        }
        if (!$this->params->has('sign')) {
            throw new InvalidRequestException('The sign is required');
        }
    }