code: func (au *LocalAuthenticator) Add(k, v string) {
  	au.mux.Lock()
  	defer au.mux.Unlock()
  	if au.kvs == nil {
  		au.kvs = make(map[string]string)
  	}
  	au.kvs[k] = v
  }
docs: // Add adds a key-value pair to the Authenticator.