public static function getGeoIPUrlExtension($url)
    {
        // check for &suffix= query param that is special to MaxMind URLs
        if (preg_match('/suffix=([^&]+)/', $url, $matches)) {
            $ext = $matches[1];
        } else {
            // use basename of url
            $filenameParts = explode('.', basename($url), 2);
            if (count($filenameParts) > 1) {
                $ext = end($filenameParts);
            } else {
                $ext = reset($filenameParts);
            }
        }

        self::checkForSupportedArchiveType($ext);

        return $ext;
    }