@Override
  protected void serializeAttributes(ByteBuffer byteBuffer) {
    PlanNodeType.SHUFFLE_SINK.serialize(byteBuffer);
    ReadWriteIOUtils.write(downStreamChannelLocationList.size(), byteBuffer);
    for (DownStreamChannelLocation downStreamChannelLocation : downStreamChannelLocationList) {
      downStreamChannelLocation.serialize(byteBuffer);
    }
  }
Responsible for creating ShuffleHelperOperator and corresponding SinkHandle
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/plan/node/sink/ShuffleSinkNode.java