code: @Override
    public OperableTrigger retrieveTrigger(String triggerKey) {
  
      synchronized (lock) {
        TriggerWrapper tw = wrappedTriggersByKey.get(triggerKey);
  
        return (tw != null) ? (OperableTrigger) tw.getTrigger().clone() : null;
      }
    }
docs: Retrieve the given <code>{@link org.quartz.triggers.Trigger}</code>.
  
  @return The desired <code>Trigger</code>, or null if there is no match.