code: @Override
      public boolean checkExists(final TriggerKey triggerKey) throws JobPersistenceException {
          return doWithLock(new LockCallback<Boolean>() {
              @Override
              public Boolean doWithLock(JedisCommands jedis) throws JobPersistenceException {
                  return storage.checkExists(triggerKey, jedis);
              }
          }, "Could not check if trigger exists: " + triggerKey);
      }
docs: Determine whether a {@link org.quartz.Trigger} with the given identifier already
  exists within the scheduler.
  
  @param triggerKey the identifier to check for
  @return true if a Trigger exists with the given identifier
  @throws org.quartz.JobPersistenceException