public void setFromScratchTimestamp(int elementNum) {
    this.time[elementNum] = scratchTimestamp.getTime();
    this.nanos[elementNum] = scratchTimestamp.getNanos();
  }
Set a field from the current value in the scratch timestamp.

This is a FAST version that assumes the caller has checked to make sure the current value in
the scratch timestamp is valid and elementNum is correctly adjusted for isRepeating.  And,
that the isNull entry has been set.  Only the output entry fields will be set by this method.

@param elementNum
storage-api/src/java/org/apache/hadoop/hive/ql/exec/vector/TimestampColumnVector.java