@Override
 public void writeTo(StreamOutput out) throws IOException {
   super.writeTo(out);
   out.writeVInt(nodes.length);
   for (NodeStats node : nodes) {
     node.writeTo(out);
   }
 }
 @Override
 public void writeTo(StreamOutput out) throws IOException {
   super.writeTo(out);
   out.writeVLong(timestamp);
   if (status == null) {
     out.writeBoolean(false);
   } else {
     out.writeBoolean(true);
     out.writeByte(status.value());
   }
   out.writeString(clusterUUID);
   nodesStats.writeTo(out);
   indicesStats.writeTo(out);
 }