@Override
        public boolean hasNext() {
            return iterator.isValid();
        }
{@link Iterator} wrapper for RocksDb Iterator {@link RocksIterator}.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/iceberg/src/main/java/org/apache/inlong/sort/iceberg/sink/collections/RocksDBDAO.java