refactor, better class namespace intergration

app/Models/Shop/Package.php

@@ -11,16 +11,16 @@ class Package extends Model
 
     public function article_family()
     {
-        return $this->belongsTo('App\Models\Shop\ArticleNature');
+        return $this->belongsTo(ArticleNature::class);
     }
 
     public function unities()
     {
-        return $this->hasMany('App\Models\Shop\Unity');
+        return $this->hasMany(Unity::class);
     }
 
     public function scopeByArticleNature($query, $id)
     {
-        return $query->where('article_family_id', $id);
+        return $query->where($this->table . '.article_family_id', $id);
     }
 }