code: func (m *CollapsingMapper) Map(e *Entity) (PilosaRecord, error) {
  	pr := PilosaRecord{}
  	if m.ColTranslator != nil {
  		col, err := m.ColTranslator.GetID(string(e.Subject))
  		if err != nil {
  			return pr, errors.Wrap(err, "getting column id from subject")
  		}
  		pr.Col = col
  	} else if m.Nexter != nil {
  		pr.Col = m.Nexter.Next()
  	} else {
  		pr.Col = string(e.Subject)
  	}
  	return pr, m.mapObj(e, &pr, []string{})
  }
docs: // Map implements the RecordMapper interface.