code: func NewPilosaKeyMapper(t Translator, colTranslator ...FieldTranslator) *PilosaKeyMapper {
  	pkm := &PilosaKeyMapper{
  		t: t,
  	}
  	if len(colTranslator) > 0 {
  		pkm.c = colTranslator[0]
  	}
  	return pkm
  }
docs: // NewPilosaKeyMapper returns a PilosaKeyMapper.