code: @Override protected void doUnschedule(JobSpecSchedule existingSchedule) {
      Preconditions.checkNotNull(existingSchedule);
      Preconditions.checkArgument(existingSchedule instanceof QuartzJobSchedule);
  
      QuartzJobSchedule quartzSchedule = (QuartzJobSchedule)existingSchedule;
      try {
        _scheduler.getScheduler().deleteJob(quartzSchedule.getQuartzTrigger().getJobKey());
      } catch (SchedulerException e) {
        throw new RuntimeException("Unscheduling failed for " + existingSchedule.getJobSpec()
                                    + ":" + e, e);
      }
    }
docs: {@inheritDoc}