Spatie\Activitylog\ActivitylogServiceProvider::determineActivityModel PHP Метод

    public static function determineActivityModel() : string
    {
        $activityModel = config('laravel-activitylog.activity_model') != null ? config('laravel-activitylog.activity_model') : Activity::class;
        if (!is_a($activityModel, Activity::class, true)) {
            throw InvalidConfiguration::modelIsNotValid($activityModel);
        }
        return $activityModel;
    }

 public function activity() : MorphMany
 {
     return $this->morphMany(ActivitylogServiceProvider::determineActivityModel(), 'subject');
 }