static public function logPublishingChange(
        Model $model,
        $action,
        Admin $admin = null)
    {
        if ($model->isDirty('public')) {
            if ($model->public) {
                static::createLog($model, 'published', $admin);
            } else if (!$model->public && $action != 'created') {
                static::createLog($model, 'unpublished', $admin);
            }
        }
    }