code: func StringsSet(in []string) map[string]struct{} {
  	if in == nil {
  		return nil
  	}
  	out := make(map[string]struct{})
  	for _, v := range in {
  		out[v] = struct{}{}
  	}
  	return out
  }
docs: // StringsSet creates set of string (map[string]struct{})
  // from a list of strings