CMS Toutorial problem with tags

Hi everyone, i’m having some problem in the tag section:
i’ve created the _getTagString method inside the article.php entity

but the prop $this->tags is empty so the function return empty string.

i’ve copy pasted all the code, but i’m missing something. i’ve also added this line inside articesTable : $this->belongsToMany(‘Tags’);


$article = $this->Articles->findBySlug($slug)->firstOrFail();

with this line cake is getting my article and all the associated tags? so inside the entity i should have it right?