@Override
    public Map<String, String> getProperties(final Map<String, String> defaultProperties, final long additionalRetentionMs) {
        // internal topic config overridden rule: library overrides < global config overrides < per-topic config overrides
        final Map<String, String> topicConfig = new HashMap<>(UNWINDOWED_STORE_CHANGELOG_TOPIC_DEFAULT_OVERRIDES);

        topicConfig.putAll(defaultProperties);

        topicConfig.putAll(topicConfigs);

        return topicConfig;
    }
Get the configured properties for this topic. If retentionMs is set then
we add additionalRetentionMs to work out the desired retention when cleanup.policy=compact,delete

@param additionalRetentionMs - added to retention to allow for clock drift etc
@return Properties to be used when creating the topic
streams/src/main/java/org/apache/kafka/streams/processor/internals/UnwindowedUnversionedChangelogTopicConfig.java