@Override
    public void toData(DataOutput out,
        SerializationContext context) throws IOException {
      super.toData(out, context);
      if (chunkStream == null) {
        out.writeInt(-1);
      } else {
        out.writeInt(numObjects);
      }
      out.writeInt(msgNum);
      out.writeBoolean(lastMsg);
      out.writeBoolean(pdxReadSerialized);
      if (chunkStream != null && numObjects > 0) {
        chunkStream.sendTo(out);
      }
    }
Return the objects in this chunk as a List, used only on receiving side
geode-core/src/main/java/org/apache/geode/distributed/internal/streaming/StreamingOperation.java