public static PlanNode deserialize(ByteBuffer byteBuffer) {
    int size = ReadWriteIOUtils.readInt(byteBuffer);
    List<String> storageGroupList = new ArrayList<>(size);
    for (int i = 0; i < size; i++) {
      storageGroupList.add(ReadWriteIOUtils.readString(byteBuffer));
    }
    PlanNodeId planNodeId = PlanNodeId.deserialize(byteBuffer);
    return new SchemaFetchMergeNode(planNodeId, storageGroupList);
  }
This class defines the scanned result merge task of schema fetcher.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/plan/node/metadata/read/SchemaFetchMergeNode.java