title: Laravel model return Undefined property::$attribute
body: <p>I have model Post with attributes: <code>id, content, image, publish_date</code>.
  In the Post model I can get all attributes but image when using <code>$this-&gt;$attr</code> it shows me Undefined property when calling $this->image. I don't know why. But when I call in the <code>Controller: Post::find(1)-&gt;image</code>, it works fine.
  Can anyone help me pls?</p>