code: void reExecutePeriodic(RunnableScheduledFuture<?> task) {
          if (canRunInCurrentRunState(true)) {
              super.getQueue().add(task);
              if (!canRunInCurrentRunState(true) && remove(task))
                  task.cancel(false);
              else
                  ensurePrestart();
          }
      }
docs: Requeues a periodic task unless current run state precludes it.
  Same idea as delayedExecute except drops task rather than rejecting.
  
  @param task the task