code: public boolean isStarted() throws MangooSchedulerException {
          boolean started;
          try {
              started = this.quartzScheduler != null && this.quartzScheduler.isStarted();
          } catch (SchedulerException e) {
              throw new MangooSchedulerException(e);
          }
          
          return started;
      }
docs: Checks if the scheduler is initialized and started
  
  @return true if the scheduler is started, false otherwise
  @throws MangooSchedulerException if an error occurred accessing the scheduler