code: func (s *AESEncryptedStorage) writeEncryptedStorage(creds map[string]storedCredential) error {
  	raw, err := json.Marshal(creds)
  	if err != nil {
  		return err
  	}
  	if err = ioutil.WriteFile(s.filename, raw, 0600); err != nil {
  		return err
  	}
  	return nil
  }
docs: // writeEncryptedStorage write the file with encrypted creds