kafka_multisource-protolib/src/main/java/com/streamsets/pipeline/stage/origin/multikafka/MultiKafkaSource.java
private Properties getKafkaProperties(Stage.Context context) {
    Properties props = new Properties();
    props.putAll(conf.kafkaOptions);

    props.setProperty("bootstrap.servers", conf.brokerURI);
    props.setProperty("group.id", conf.consumerGroup);
    props.setProperty("max.poll.records", String.valueOf(batchSize));
    props.setProperty(KafkaConstants.KEY_DESERIALIZER_CLASS_CONFIG, conf.keyDeserializer.getKeyClass());
    props.setProperty(KafkaConstants.VALUE_DESERIALIZER_CLASS_CONFIG, conf.valueDeserializer.getValueClass());
    props.setProperty(KafkaConstants.CONFLUENT_SCHEMA_REGISTRY_URL_CONFIG, StringUtils.join(conf.dataFormatConfig.schemaRegistryUrls, ","));
    props.setProperty(KafkaConstants.AUTO_COMMIT_OFFEST, "false");

    if(context.isPreview()) {
      props.setProperty(KafkaConstants.AUTO_OFFSET_RESET_CONFIG, KafkaConstants.AUTO_OFFSET_RESET_PREVIEW_VALUE);
    }

    return props;
  }
private Properties getKafkaProperties(Stage.Context context) {
    Properties props = new Properties();
    props.putAll(conf.kafkaOptions);

    props.setProperty("bootstrap.servers", conf.brokerURI);
    props.setProperty("group.id", conf.consumerGroup);
    props.setProperty("max.poll.records", String.valueOf(batchSize));
    props.setProperty(KafkaConstants.KEY_DESERIALIZER_CLASS_CONFIG, conf.keyDeserializer.getKeyClass());
    props.setProperty(KafkaConstants.VALUE_DESERIALIZER_CLASS_CONFIG, conf.valueDeserializer.getValueClass());
    props.setProperty(KafkaConstants.CONFLUENT_SCHEMA_REGISTRY_URL_CONFIG, StringUtils.join(conf.dataFormatConfig.schemaRegistryUrls, ","));
    props.setProperty(KafkaConstants.AUTO_COMMIT_OFFEST, "false");

    if(context.isPreview()) {
      props.setProperty(KafkaConstants.AUTO_OFFSET_RESET_CONFIG, KafkaConstants.AUTO_OFFSET_RESET_PREVIEW_VALUE);
    }

    return props;
  }
no trespassing...