private static boolean matchingTopic(FetchResponseData.FetchableTopicResponse previousTopic, TopicIdPartition currentTopic) {
        if (previousTopic == null)
            return false;
        if (!previousTopic.topicId().equals(Uuid.ZERO_UUID))
            return previousTopic.topicId().equals(currentTopic.topicId());
        else
            return previousTopic.topic().equals(currentTopic.topicPartition().topic());

    }
@return The size in bytes of the records. 0 is returned if records of input partition is null.
clients/src/main/java/org/apache/kafka/common/requests/FetchResponse.java