buf.append("\"os\":{");
        final OsProbe osProbe = OsProbe.getInstance();
        buf.append("\"memory\":{");
        buf.append("\"physical\":{");
        append(buf, "free", () -> osProbe.getFreePhysicalMemorySize()).append(',');
        append(buf, "total", () -> osProbe.getTotalPhysicalMemorySize());
        buf.append("},");
        buf.append("\"swap_space\":{");

        osObj.memory = osMemoryObj;
        final OsMemoryPhysicalObj osMemoryPhysicalObj = new OsMemoryPhysicalObj();
        osMemoryObj.physical = osMemoryPhysicalObj;
        osMemoryPhysicalObj.free = osProbe.getFreePhysicalMemorySize();
        osMemoryPhysicalObj.total = osProbe.getTotalPhysicalMemorySize();
        final OsMemorySwapSpaceObj osMemorySwapSpaceObj = new OsMemorySwapSpaceObj();
        osMemoryObj.swapSpace = osMemorySwapSpaceObj;