public class Test {
    public static void main(String[] args) throws Exception {
        try (Connection nc = Nats.connect()) {
            JetStreamManagement jsm = nc.jetStreamManagement();

            String streamName = "EVENTS";
            jsm.addStream(StreamConfiguration.builder()
                    .name(streamName)
                    .subjects("event.>")
                    .build());

            StreamContext streamContext = nc.getStreamContext(streamName);
            
            // Setting maxBatch=1, so we shouldn't allow fetching more messages at once.
            ConsumerConfiguration consumerConfig = ConsumerConfiguration.builder().maxBatch(1).build();
            ConsumerContext consumerContext = streamContext.createOrUpdateConsumer(consumerConfig);

            int count = 0;
            
            // Fetching a batch of 100 messages is not allowed, so we rightfully don't get any messages and wait for timeout.
            // But we don't get informed about the status message.
            try (FetchConsumer fetchConsumer = consumerContext.fetchMessages(100)) {
                Message msg;
                while ((msg = fetchConsumer.nextMessage()) != null) {
                    msg.ack();
                    count++;
                }
            }

            System.out.printf("Received %d messages.", count);
        }
    }
}