private long getOpenSocketCount() {
        OSProcess process = os.getProcess(os.getProcessId());
        return process.getOpenFiles();
    }
ref https://github.com/jrask/micrometer-oshi-binder
@author intr3p1d
collector-monitor/src/main/java/com/navercorp/pinpoint/collector/monitor/micrometer/binder/NetworkMetricsBinder.java