@Override
  public HiveBatchContext next() {
    advance();
    advanced = false;
    return new HiveBatchContext(batch, vrbCtx, rowOffset);
  }
Iterator wrapper around Hive's VectorizedRowBatch producer (MRv1 implementing) record readers.
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/hive/vector/HiveBatchIterator.java