code: func ParseHumanReadableKey(key string) ([]byte, error) {
  	if !strings.HasPrefix(key, humanReadablePrefix) {
  		return nil, fmt.Errorf("invalid key string")
  	}
  	keyBytes, err := base64.RawStdEncoding.DecodeString(strings.TrimPrefix(key, humanReadablePrefix))
  	if err != nil {
  		return nil, fmt.Errorf("invalid key string")
  	}
  	return keyBytes, nil
  }
docs: // ParseHumanReadableKey returns a key as bytes from recognized serializations of
  // said keys