public Iterator<DataBlockIndex> iterator() {
            AtomicInteger getIndex = new AtomicInteger(0);
            return new Iterator<>() {
                @Override
                public boolean hasNext() {
                    return getIndex.get() < count;
                }

                @Override
                public DataBlockIndex next() {
                    return get(getIndex.getAndIncrement());
                }
            };
        }
@param dataBlockSize The total size of the data blocks, which equals to index start position.
@param indexBlock    raw index data.
s3stream/src/main/java/com/automq/stream/s3/ObjectReader.java