@Override
  public void toData(DataOutput out,
      SerializationContext context) throws IOException {
    super.toData(out, context);
    DataSerializer.writeObject(key, out);
  }
Send RemoteFetchVersionMessage to the recipient for the given key

@return the processor used to fetch the VersionTag for the key
@throws RemoteOperationException if the member is no longer available
geode-core/src/main/java/org/apache/geode/internal/cache/tx/RemoteFetchVersionMessage.java