@Override
  public VectorizedRowBatch createValue() {
    return LlapHiveUtils.findMapWork(job).getVectorizedRowBatchCtx().createVectorizedRowBatch();
  }
Basically an MR1 API implementing wrapper for transferring VectorizedRowBatch's produced by
IcebergInputformat$IcebergRecordReader which relies on the MR2 API format.
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/hive/vector/HiveIcebergVectorizedRecordReader.java