private void messageReceived(TopicPartition topicPartition, byte[] payload, long sendTimeNanos) {
        if (preparing && config.awaitTopicReady && (config.catchupTopicPrefix == null || config.catchupTopicPrefix.isEmpty())) {
            readyPartitions.add(topicPartition);
        }
        stats.messageReceived(payload.length, sendTimeNanos);
    }
Partitions that are ready to be consumed.
Only used during the initial topic readiness check, which is, {@link #preparing} is true.
tools/src/main/java/org/apache/kafka/tools/automq/PerfCommand.java