code: func (s *Set) Allow(pubKeyHashes ...string) error {
  	for _, pubKeyHash := range pubKeyHashes {
  		parts := strings.Split(pubKeyHash, ":")
  		if len(parts) != 2 {
  			return errors.New("invalid public key hash, expected \"format:value\"")
  		}
  		format, value := parts[0], parts[1]
  
  		switch strings.ToLower(format) {
  		case "sha256":
  			return s.allowSHA256(value)
  		default:
  			return errors.Errorf("unknown hash format %q", format)
  		}
  	}
  	return nil
  }
docs: // Allow adds an allowed public key hash to the Set