@Override
    public List<String> ack(List<Message> messages) {
        for (Message msg : messages) {
            queueDAO.ack(queueName, msg.getId());
        }
        return messages.stream().map(Message::getId).collect(Collectors.toList());
    }
An {@link ObservableQueue} implementation using the underlying {@link QueueDAO} implementation.
core/src/main/java/com/netflix/conductor/core/events/queue/ConductorObservableQueue.java