code: func UnflattenDatums(datums []types.Datum, fts []*types.FieldType, loc *time.Location) ([]types.Datum, error) {
  	for i, datum := range datums {
  		ft := fts[i]
  		uDatum, err := unflatten(datum, ft, loc)
  		if err != nil {
  			return datums, errors.Trace(err)
  		}
  		datums[i] = uDatum
  	}
  	return datums, nil
  }
docs: // UnflattenDatums converts raw datums to column datums.