protected function filterBrowserNames(array $userAgent)
    {
        // IE11 hasn't 'MSIE' in its user agent string
        if (empty($userAgent['browser_name']) && $userAgent['browser_engine'] === 'trident' && strpos($userAgent['string'], 'rv:')) {
            $userAgent['browser_name'] = 'msie';
            $userAgent['browser_version'] = preg_replace('|.+rv:([0-9]+(?:\.[0-9]+)+).+|', '$1', $userAgent['string']);

            return $userAgent;
        }

        return $userAgent;
    }