protected void writeInternal(ObjectDataOutput out) throws IOException {
   super.writeInternal(out);
   out.writeUTF(caller);
   out.writeLong(ttl);
 }
 @Override
 protected void writeInternal(ObjectDataOutput out) throws IOException {
   super.writeInternal(out);
   out.writeLong(recordId);
   out.writeData(value);
 }