code: func (s *SessionClient) MachineLogin(ctx context.Context, tokenID, tokenSecret string) error {
  
  	ID, err := identity.DecodeFromString(tokenID)
  	if err != nil {
  		return err
  	}
  
  	secret, err := base64.NewFromString(tokenSecret)
  	if err != nil {
  		return err
  	}
  
  	login := apitypes.MachineLogin{
  		TokenID: &ID,
  		Secret:  secret,
  	}
  
  	rawLogin, err := json.Marshal(login)
  	if err != nil {
  		return err
  	}
  	return performLogin(ctx, s, "machine", rawLogin)
  }
docs: // MachineLogin logs the user in using the provided token id and secret