title: Check if session key exists in Laravel 5.1?
body: <p>I'm trying to check it a session key has already been set inside a controller. The documentation states that it is possible to check if an item exists in an array and that's it.</p>
  
  <p><a href="http://laravel.com/docs/5.1/session" rel="noreferrer">http://laravel.com/docs/5.1/session</a></p>