oldConsumerHolder.getConsumer()已经执行close()，可为何还要assign()

[xinzhuxiansheng]

//已经close closeConsumer(oldConsumerHolder);

        ConsumerHolder newConsumerHolder = getOrAddConsumer(topicId);
        if (oldConsumerHolder.getAssignments() != null) {
            newConsumerHolder.setAssignments(oldConsumerHolder.getAssignments());

// oldCOnsumerHolder.getConsumer() 没必须要assign了吧，作者，这里是笔误？ 有点没太明白 oldConsumerHolder.getConsumer().assign(oldConsumerHolder.getAssignments()); } else if (oldConsumerHolder.getConsumerRebalanceListener() != null) { newConsumerHolder.setConsumerRebalanceListener(oldConsumerHolder.getConsumerRebalanceListener()); newConsumerHolder.getConsumer().subscribe(Arrays.asList(topicId), oldConsumerHolder.getConsumerRebalanceListener()); } else { newConsumerHolder.getConsumer().subscribe(Arrays.asList(topicId)); }