code: func (l *Language) IsSet(key string) bool {
  	key = strings.ToLower(key)
  
  	key = strings.ToLower(key)
  	if !globalOnlySettings[key] {
  		if _, ok := l.settings[key]; ok {
  			return true
  		}
  	}
  	return l.Cfg.IsSet(key)
  
  }
docs: // IsSet checks whether the key is set in the language or the related config store.