code: public static Scheduler createScheduler(int threadPoolSize, String annotatedJobsPackageName)
        throws SundialSchedulerException {
  
      if (scheduler == null) {
        try {
          scheduler = new SchedulerFactory().getScheduler(threadPoolSize, annotatedJobsPackageName);
  
        } catch (SchedulerException e) {
          throw new SundialSchedulerException("COULD NOT CREATE SUNDIAL SCHEDULER!!!", e);
        }
      }
      return scheduler;
    }
docs: Creates the Sundial Scheduler
  
  @param threadPoolSize the thread pool size used by the scheduler
  @param annotatedJobsPackageName A comma(,) or colon(:) can be used to specify multiple packages
  to scan for Jobs.
  @return