@VisibleForTesting
    Configuration getConfiguration() {
        return toConfiguration(props);
    }
Get a kafkaSourceBuilder to build a {@link KafkaSource}.

@return a Kafka source builder.
inlong-sort/sort-flink/sort-flink-v1.15/sort-connectors/kafka/src/main/java/org/apache/inlong/sort/kafka/source/KafkaSource.java