@Override
    public void fromData(DataInput in,
        DeserializationContext context) throws IOException, ClassNotFoundException {
      super.fromData(in, context);
      processorId = in.readInt();
    }
override in subclass to provide reply data. terminate by returning Token.END_OF_STREAM
geode-core/src/main/java/org/apache/geode/distributed/internal/streaming/StreamingOperation.java