@Override public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException { builder.startObject(Fields.OS); builder.field(Fields.TIMESTAMP, getTimestamp()); cpu.toXContent(builder, params); mem.toXContent(builder, params); swap.toXContent(builder, params); if (cgroup != null) { cgroup.toXContent(builder, params); } builder.endObject(); return builder; }