buf.append("},");
        buf.append("\"swap_space\":{");
        append(buf, "free", () -> osProbe.getFreeSwapSpaceSize()).append(',');
        append(buf, "total", () -> osProbe.getTotalSwapSpaceSize());
        buf.append('}');
        buf.append("},");
        buf.append("\"cpu\":{");
        append(buf, "percent", () -> osProbe.getSystemCpuPercent());
        final OsStats osStats = osProbe.osStats();