code: func NewWithNamespace(name string) string {
  	var u uuid.UUID
  
  	switch {
  	case name == "":
  		u = uuid.New()
  	case strings.HasPrefix(name, "http"):
  		u = uuid.NewSHA1(uuid.NameSpaceURL, []byte(name))
  	default:
  		u = uuid.NewSHA1(uuid.NameSpaceDNS, []byte(name))
  	}
  
  	return DefaultEncoder.Encode(u)
  }
docs: // NewWithNamespace returns a new UUIDv5 (or v4 if name is empty), encoded with base57.