@SuppressWarnings("unchecked")
    public long getCurrentRegionId() {
        return ((Pair<Long, Long>) this.attach).getKey();
    }
The best practice is to call this method only once
and keep a copy of it yourself.
jraft-rheakv/rheakv-core/src/main/java/com/alipay/sofa/jraft/rhea/storage/KVOperation.java