public static function boot()
 {
     parent::boot();
     ArticleImage::creating(function ($image) {
         $image->order = ArticleImage::where('blog_article_id', '=', $image->blog_article_id)->count() + 1;
     });
     ArticleImage::deleted(function ($image) {
         $images = ArticleImage::where('blog_article_id', '=', $image->blog_article_id)->orderBy('order', 'asc')->get();
         $i = 1;
         foreach ($images as $image) {
             $image->order = $i;
             $i++;
             $image->save();
         }
     });
 }