code: func (k *Apk) MainActivity() (activity string, err error) {
  	for _, act := range k.manifest.App.Activities {
  		for _, intent := range act.IntentFilters {
  			if isMainIntentFilter(intent) {
  				return act.Name, nil
  			}
  		}
  	}
  	for _, act := range k.manifest.App.ActivityAliases {
  		for _, intent := range act.IntentFilters {
  			if isMainIntentFilter(intent) {
  				return act.TargetActivity, nil
  			}
  		}
  	}
  
  	return "", errors.New("No main activity found")
  }
docs: // MainActivity returns the name of the main activity.