code: func NewPrefixSecret() (PrefixSecret, error) {
  	buf := make([]byte, PrefixSecretLength)
  	if _, err := rand.Read(buf); err != nil {
  		return nil, err
  	}
  
  	value := PrefixSecret(buf)
  	if err := value.Validate(); err != nil {
  		panic(err)
  	}
  	return value, nil
  }
docs: // NewPrefixSecret generates a new, default-length secret parameter.