kafka_multisource-protolib/src/main/java/com/streamsets/pipeline/stage/origin/multikafka/MultiKafkaRawSourcePreviewer.java
private <T> String convertToRawListString(Collection<T> collection) {
    return "[ " + collection.stream().map(x -> '"'+x.toString()+'"').collect(Collectors.joining(", ")) + " ]";
  }
private <T> String convertToRawListString(Collection<T> collection) {
    return "[ " + collection.stream().map(x -> '"'+x.toString()+'"').collect(Collectors.joining(", ")) + " ]";
  }
theoretically they could just copy/paste the output into the Topics bulk edit field in the Kafka config