protected function getOperatingSystem()
    {
        $osRaw = strtolower(PHP_OS);
        
        if (strpos($osRaw, 'linux') !== false) {
            return RequestAbstract::OS_LINUX;
        } else if (strpos($osRaw, 'windows') !== false) {
            return RequestAbstract::OS_WINDOWS;
        } else {
            return RequestAbstract::OS_UNKNOWN;
        }
    }