title: facebook graph api getGraphObject()->asArray() returns null
body: <p>so I have this:</p>
  
  <p><code>$pages = (new FacebookRequest($session, 'GET', '/search?q=Computers/Technology&amp;fields=likes'))-&gt;execute()-&gt;getGraphObject()-&gt;asArray();</code></p>
  
  <p>I just want to get the likes of those pages, so I did <code>$pages["likes"]</code> also tried <code>$pages-&gt;likes</code> and I get null.
  But when i do <code>var_dump($pages)</code> it shows all the data. So why can't I get just the likes?</p>