Identify the error in this Kafka Streams code snippet for exactly-once processing:

Identify the error in this Kafka Streams code snippet for exactly-once processing:

props.put("enable.idempotence", "true");
props.put("transactional.id", "txn-1");
KafkaProducer producer = new KafkaProducer(props);
producer.beginTransaction();
producer.send(record);
// Missing commit or abort here
producer.close();