code: public void start () throws SchedulerException
    {
  
      if (m_bShuttingDown || m_bClosed)
      {
        throw new SchedulerException ("The Scheduler cannot be restarted after shutdown() has been called.");
      }
  
      // QTZ-212 : calling new schedulerStarting() method on the listeners
      // right after entering start()
      notifySchedulerListenersStarting ();
  
      if (m_aInitialStart == null)
      {
        m_aInitialStart = new Date ();
        m_aResources.getJobStore ().schedulerStarted ();
        _startPlugins ();
      }
      else
      {
        m_aResources.getJobStore ().schedulerResumed ();
      }
  
      m_aSchedThread.togglePause (false);
  
      LOGGER.info ("Scheduler " + m_aResources.getUniqueIdentifier () + " started.");
  
      notifySchedulerListenersStarted ();
    }
docs: <p>
  Starts the <code>QuartzScheduler</code>'s threads that fire
  <code>{@link com.helger.quartz.ITrigger}s</code>.
  </p>
  <p>
  All <code>{@link com.helger.quartz.ITrigger}s</code> that have misfired
  will be passed to the appropriate TriggerListener(s).
  </p>