@Override
  protected void prepareBuffer() {
    super.prepareBuffer();
    if (replicaMetadataResponseInfoList != null) {
      bufferToSend.writeInt(replicaMetadataResponseInfoList.size());
      for (ReplicaMetadataResponseInfo replicaMetadataResponseInfo : replicaMetadataResponseInfoList) {
        replicaMetadataResponseInfo.writeTo(bufferToSend);
      }
    } else {
      bufferToSend.writeInt(0);
    }
  }
The response for a ReplicaMetadataRequest. This returns the new entries found
and the new token that could be used for future searches
ambry-protocol/src/main/java/com/github/ambry/protocol/ReplicaMetadataResponse.java