code: func (i *smallIndex) Values() []string {
  	// In principle this method should return [][]byte because all the other
  	// methods deal in []byte keys. However, in practice, where it's used
  	// wants a []string and it's easier to just create that here rather than
  	// having to convert both here and there...
  
  	i.mut.Lock()
  	vals := make([]string, 0, len(i.val2id))
  	for val := range i.val2id {
  		vals = append(vals, val)
  	}
  	i.mut.Unlock()
  
  	sort.Strings(vals)
  	return vals
  }
docs: // Values returns the set of values in the index