public static CollectNode deserialize(ByteBuffer byteBuffer) {
    int size = ReadWriteIOUtils.readInt(byteBuffer);
    List<Symbol> outputSymbols = new ArrayList<>(size);
    while (size-- > 0) {
      outputSymbols.add(Symbol.deserialize(byteBuffer));
    }
    PlanNodeId planNodeId = PlanNodeId.deserialize(byteBuffer);
    return new CollectNode(planNodeId, outputSymbols);
  }
CollectNode output the content of children. Normally it will output the child one by one, but in
some cases, while some children are blocked, it may output the content of other children.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/node/CollectNode.java