@Override
    public void toData(DataOutput dout,
        SerializationContext context) throws IOException {
      super.toData(dout, context);
      dout.writeInt(processorId);
      DataSerializer.writeHashMap(channelState, dout);
      DataSerializer.writeObject(requestingMember, dout);
      dout.writeBoolean(isSingleFlushTo);
    }
whether this is a simple request/response two-party flush or (false) a proxied flush
geode-core/src/main/java/org/apache/geode/internal/cache/StateFlushOperation.java