protected function checkSSHConnection($server = null, $ssh_config_file = null, $verbose = false)
    {
        $server = $server ? $server : $this->hostNameForConfigFile();
        $ssh_config_file =  $ssh_config_file ? $ssh_config_file : $this->sshConfigFile();
        if ($verbose) {
            $this->info("timeout 10 ssh -F $ssh_config_file -q " . $server . ' exit; echo $?');
        }

        $ret = exec("timeout 10 ssh -F $ssh_config_file -q " . $server . ' "exit"; echo $?');
        if ($ret == 0) {
            return true;
        }
        return false;
    }