code: @Override
      public OperableTrigger retrieveTrigger(final TriggerKey triggerKey) throws JobPersistenceException {
          return doWithLock(new LockCallback<OperableTrigger>() {
              @Override
              public OperableTrigger doWithLock(JedisCommands jedis) throws JobPersistenceException {
                  return storage.retrieveTrigger(triggerKey, jedis);
              }
          }, "Could not retrieve trigger.");
      }
docs: Retrieve the given <code>{@link org.quartz.Trigger}</code>.
  
  @param triggerKey the key of the desired trigger
  @return The desired <code>Trigger</code>, or null if there is no
  match.