public function cpu_usage()
    {
        if ($this->host_os === 'WINDOWS') {
            $wmi = new \COM("winmgmts:\\\\.\\root\\cimv2");
            $cpus = $wmi->ExecQuery("SELECT LoadPercentage FROM Win32_Processor");

            foreach ($cpus as $cpu) {
                $return = $cpu->LoadPercentage;
            }
        } else {
            $return = shell_exec('top -d 0.5 -b -n2 | grep "Cpu(s)"|tail -n 1 | awk \'{print $2 + $4}\'');
        }
        return trim($return);
    }