void removeTopicEntryForBroker(Uuid topicId, int brokerId) {
        Map<Uuid, int[]> topicMap = isrMembers.get(brokerId);
        if (topicMap != null) {
            topicMap.remove(topicId);
        }
    }
Update our records of a partition's ISR.

@param topicId       The topic ID of the partition.
@param partitionId   The partition ID of the partition.
@param prevIsr       The previous ISR, or null if the partition is new.
@param nextIsr       The new ISR, or null if the partition is being removed.
@param prevLeader    The previous leader, or NO_LEADER if the partition had no leader.
@param nextLeader    The new leader, or NO_LEADER if the partition now has no leader.
metadata/src/main/java/org/apache/kafka/controller/BrokersToIsrs.java