code: static int compare (final Date nextFireTime1,
                          final int priority1,
                          final TriggerKey key1,
                          final Date nextFireTime2,
                          final int priority2,
                          final TriggerKey key2)
      {
        if (nextFireTime1 != null || nextFireTime2 != null)
        {
          if (nextFireTime1 == null)
            return 1;
          if (nextFireTime2 == null)
            return -1;
          if (nextFireTime1.before (nextFireTime2))
            return -1;
          if (nextFireTime1.after (nextFireTime2))
            return 1;
        }
  
        int comp = priority2 - priority1;
        if (comp == 0)
          comp = key1.compareTo (key2);
        return comp;
      }
docs: This static method exists for comparator in TC clustered quartz