@InterfaceAudience.Private
  public synchronized boolean isChoreScheduled(ScheduledChore chore) {
    return chore != null && scheduledChores.containsKey(chore)
      && !scheduledChores.get(chore).isDone();
  }
Returns true when the chore is scheduled with the implementer of this interface
hbase-common/src/main/java/org/apache/hadoop/hbase/ChoreService.java