protected function uptime()
    {
        $linfo = $this->linfo->getParser();

        $uptime = $booted_at = null;

        $systemUptime = $this->ifExists($linfo->getUpTime());

        if (! empty($systemUptime['text'])) {
            $uptime = $systemUptime['text'];
        }

        if (! empty($systemUptime['bootedTimestamp'])) {
            $booted_at = date('Y-m-d H:i:s', $systemUptime['bootedTimestamp']);
        }

        $this->results['server']['uptime'] = compact(
            'uptime', 'booted_at'
        );

        return $this;
    }