@Override
 public void writeTo(StreamOutput out) throws IOException {
   super.writeTo(out);
   indicesLevelRequest.writeTo(out);
   int size = shards.size();
   out.writeVInt(size);
   for (int i = 0; i < size; i++) {
     shards.get(i).writeTo(out);
   }
   out.writeString(nodeId);
 }
 @Override
 public void writeTo(StreamOutput out) throws IOException {
   out.writeVInt(shardId);
   request.writeTo(out);
 }