code: func (pwm *Manager) Validate(username, securityCode string) (bool, error) {
  
  	var storedSecret userSecret
  	if err := pwm.collection.Find(bson.M{"username": username}).One(&storedSecret); err != nil {
  		if err == mgo.ErrNotFound {
  			log.Debug("No totpsecret found for this user")
  			return false, nil
  		}
  		log.Debug(err)
  		return false, err
  	}
  	token := TokenFromSecret(storedSecret.Secret)
  	match := token.Validate(securityCode)
  	return match, nil
  }
docs: //Validate checks the totp code for a specific username