code: public List<JobListener> getInternalJobListeners() {
  
      synchronized (internalJobListeners) {
        return java.util.Collections.unmodifiableList(
            new LinkedList<JobListener>(internalJobListeners.values()));
      }
    }
docs: Get a List containing all of the <code>{@link org.quartz.listeners.JobListener}</code>s in the
  <code>Scheduler</code>'s <i>internal</i> list.