@Override
    public boolean decode(final byte[] bs) {
        if (bs.length < 1) {
            return false;
        }
        short val = Bits.getShort(bs, 0);
        this.isOldStorageExist = val == 1;
        return true;
    }
This checkpoint is used for saving whether the oldStorage in HybridStorage is shutdown
jraft-extension/java-log-storage-impl/src/main/java/com/alipay/sofa/jraft/storage/file/assit/HybridStorageStatusCheckpoint.java