code: func NewCollapsingMapper() *CollapsingMapper {
  	return &CollapsingMapper{
  		Translator:    NewMapTranslator(),
  		ColTranslator: NewNexterFieldTranslator(),
  		Framer:        &DashField{},
  		Nexter:        NewNexter(),
  	}
  }
docs: // NewCollapsingMapper returns a CollapsingMapper with basic implementations of
  // its components. In order to track mapping of Pilosa columns to records, you
  // must replace the ColTranslator with something other than a
  // NexterFieldTranslator which just allocates ids and does not store a mapping.