@Override
 public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
   builder.field("timestamp", getTimestamp());
   builder.field(Fields.CLUSTER_NAME, getClusterName().value());
   if (params.paramAsBoolean("output_uuid", false)) {
     builder.field(Fields.UUID, clusterUUID);
   }
   if (status != null) {
     builder.field(Fields.STATUS, status.name().toLowerCase(Locale.ROOT));
   }
   builder.startObject(Fields.INDICES);
   indicesStats.toXContent(builder, params);
   builder.endObject();
   builder.startObject(Fields.NODES);
   nodesStats.toXContent(builder, params);
   builder.endObject();
   return builder;
 }