code: public ThreadGroup getSchedulerThreadGroup ()
    {
      if (m_aThreadGroup == null)
      {
        m_aThreadGroup = new ThreadGroup ("MiniQuartzScheduler:" + getSchedulerName ());
        if (m_aResources.getMakeSchedulerThreadDaemon ())
        {
          m_aThreadGroup.setDaemon (true);
        }
      }
  
      return m_aThreadGroup;
    }
docs: <p>
  Returns the name of the thread group for Quartz's main threads.
  </p>