public HiveIntervalDayTime asScratchIntervalDayTime(int elementNum) {
    scratchIntervalDayTime.set(totalSeconds[elementNum], nanos[elementNum]);
    return scratchIntervalDayTime;
  }
Return the scratch HiveIntervalDayTime object set from a row.
We assume the entry has already been NULL checked and isRepeated adjusted.
@param elementNum
@return
storage-api/src/java/org/apache/hadoop/hive/ql/exec/vector/IntervalDayTimeColumnVector.java