@Override
    public void deleteGroupOffsetInfo(
            Map<String, Map<String, Set<Integer>>> groupTopicPartMap) {
        StringBuilder strBuff = new StringBuilder(512);
        for (Map.Entry<String, Map<String, Set<Integer>>> entry : groupTopicPartMap.entrySet()) {
            if (entry.getKey() == null
                    || entry.getValue() == null
                    || entry.getValue().isEmpty()) {
                continue;
            }
            String basePath = strBuff.append(this.consumerZkDir).append("/")
                    .append(entry.getKey()).append("/offsets").toString();
            strBuff.delete(0, strBuff.length());
            Map<String, Set<Integer>> topicPartMap = entry.getValue();
            for (Map.Entry<String, Set<Integer>> topicEntry : topicPartMap.entrySet()) {
                if (topicEntry.getKey() == null
                        || topicEntry.getValue() == null
                        || topicEntry.getValue().isEmpty()) {
                    continue;
                }
                Set<Integer> partIdSet = topicEntry.getValue();
                for (Integer partitionId : partIdSet) {
                    String offsetNode = strBuff.append(basePath).append("/")
                            .append(topicEntry.getKey()).append("/")
                            .append(brokerId).append(TokenConstants.HYPHEN)
                            .append(partitionId).toString();
                    strBuff.delete(0, strBuff.length());
                    ZKUtil.delZNode(this.zkw, offsetNode);
                }
                String parentNode = strBuff.append(basePath).append("/")
                        .append(topicEntry.getKey()).toString();
                strBuff.delete(0, strBuff.length());
                chkAndRmvBlankParentNode(parentNode);
            }
            chkAndRmvBlankParentNode(basePath);
            String parentNode = strBuff.append(this.consumerZkDir)
                    .append("/").append(entry.getKey()).toString();
            strBuff.delete(0, strBuff.length());
            chkAndRmvBlankParentNode(parentNode);
        }
    }
Get offset stored in zookeeper, if not found or error, set null

@param groupTopicPartMap   the group topic-partition map
inlong-tubemq/tubemq-server/src/main/java/org/apache/inlong/tubemq/server/broker/offset/offsetstorage/ZkOffsetStorage.java