@Override
  public void stringifyValue(StringBuilder buffer, int row) {
    if (isRepeating) {
      row = 0;
    }
    if (noNulls || !isNull[row]) {
      scratchIntervalDayTime.set(totalSeconds[row], nanos[row]);
      buffer.append(scratchIntervalDayTime.toString());
    } else {
      buffer.append("null");
    }
  }
Set the convenience writable object stored by this column vector
@param scratchWritable
storage-api/src/java/org/apache/hadoop/hive/ql/exec/vector/IntervalDayTimeColumnVector.java