in src/main/java/com/amazon/kinesis/kafka/AmazonKinesisSinkTask.java [312:318]
public void open(Collection<TopicPartition> partitions) {
if (singleKinesisProducerPerPartition) {
for (TopicPartition topicPartition : partitions) {
producerMap.put(topicPartition.partition() + "@" + topicPartition.topic(), getKinesisProducer());
}
}
}