public long getLevelScheduledTime() {
    return levelScheduledTime;
  }
Occupied time in particular level of this task. The higher this value is, the later the task
with this Priority will be polled out by a PriorityQueue.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/schedule/queue/multilevelqueue/Priority.java