BuiltInPartitioner createBuiltInPartitioner(LogContext logContext, String topic, int stickyBatchSize) {
        return new BuiltInPartitioner(logContext, topic, stickyBatchSize);
    }
Get the deque for the given topic-partition, creating it if necessary.
clients/src/main/java/org/apache/kafka/clients/producer/internals/RecordAccumulator.java