}
    }

    private void appendJvmStats(final StringBuilder buf) {
        buf.append("\"jvm\":{");
        final JvmStats jvmStats = JvmStats.jvmStats();
        final Mem mem = jvmStats.getMem();
        buf.append("\"memory\":{");
        buf.append("\"heap\":{");
        append(buf, "used", () -> mem.getHeapUsed().getBytes()).append(',');