code: func (s *session) Logout() error {
  	s.mutex.Lock()
  	defer s.mutex.Unlock()
  
  	if s.Type() == apitypes.NotLoggedIn {
  		return createNotLoggedInError()
  	}
  
  	s.sessionType = apitypes.NotLoggedIn
  	s.identity = nil
  	s.auth = nil
  
  	s.token.Destroy()
  	s.passphrase.Destroy()
  	s.token = nil
  	s.passphrase = nil
  
  	return nil
  }
docs: // Logout resets all values to the logged out state