@Override
          public boolean hasNext() throws IOException {
            throw new UnsupportedOperationException();
          }
Wraps an LLAP vectorized record reader to a simple ORC record reader for our delete delta reading effort here.
Assumes VectorizedRowBatch type is used in upstream record reader, will not iterate row-by-row.
@param rr
@return
ql/src/java/org/apache/hadoop/hive/ql/io/orc/VectorizedOrcAcidRowBatchReader.java