private function getUrlToOldApi($method, array $params, $format)
    {
        $queryString = sprintf(
            '?apikey=%s&format=%s&method=%s%s',
            $this->getApiKey(),
            $format,
            $method,
            $this->paramsQueryStringBuilder($params)
        );

        return sprintf(
            $this::API_URL,
            $this->getDc(),
            $this->getApiVersion(),
            $queryString
        );
    }