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@Override
public Class<? extends TopicNameExtractor> topicNameExtractor() {
    if (topicNameExtractor instanceof StaticTopicNameExtractor)
        return null;
    else
        return topicNameExtractor.getClass();
}

For the string description, output the topic name if dynamic routing is not used. Otherwise, output the toString value of the TopicNameExtractor. This allows for the user to provide a better description of the topic name extractor besides just its class name.

Compatibility, Deprecation, and Migration Plan

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