title: Getting users Facebook friends with php throws exception
body: <p>I'm trying to get a list of the users friends with php but it keeps throwing an exception the code is the same from Facebook for developers docs 
  <a href="https://developers.facebook.com/docs/graph-api/reference/v3.0/user/friends" rel="nofollow noreferrer">https://developers.facebook.com/docs/graph-api/reference/v3.0/user/friends</a></p>
  
  <p>here is my code</p>
  
  <pre><code>$fb = new \Facebook\Facebook([
          'app_id' =&gt; APP_ID,
          'app_secret' =&gt; APP_SECRET,
          'default_graph_version' =&gt; DEFAULT_GRAPH_VERSION,
          //'access_token' =&gt; '{'.$fbToken.'}', // optional
      ]);
  
  try {
              $response = $fb-&gt;get('/friends', $fbToken);
          } catch(FacebookExceptionsFacebookResponseException $e) {
              echo 'Graph returned an error: ' . $e-&gt;getMessage();
              exit;
          } catch(FacebookExceptionsFacebookSDKException $e) {
              echo 'Facebook SDK returned an error: ' . $e-&gt;getMessage();
              exit;
          }
  
          $graphNode = $response-&gt;getGraphNode();
  </code></pre>
  
  <p>And here is the stacktrace of the error</p>
  
  <pre><code>[03-Jul-2018 07:29:33 UTC] PHP Fatal error:  Uncaught exception 'Facebook\Exceptions\FacebookSDKException' with message 'Unable to convert response from Graph to a GraphNode because the response looks like a GraphEdge. Try using GraphNodeFactory::makeGraphEdge() instead.' in /facebook/Facebook/GraphNodes/GraphNodeFactory.php:224
  Stack trace:
  #0 /facebook/Facebook/GraphNodes/GraphNodeFactory.php(93): Facebook\GraphNodes\GraphNodeFactory-&gt;validateResponseCastableAsGraphNode()
  #1 /facebook/Facebook/FacebookResponse.php(289): Facebook\GraphNodes\GraphNodeFactory-&gt;makeGraphNode(NULL)
  #2 {main}
    thrown in /facebook/Facebook/GraphNodes/GraphNodeFactory.php on line 224
  </code></pre>