Retrieve feed from facebook - sdk 4.0 php

<?php
session_start();

define('__ROOT__', dirname(dirname(dirname(__FILE__))));
require (__ROOT__.'/resources/facebook-php-sdk-v4-4.0-dev/autoload.php');

// added in v4.0.5
use Facebook\FacebookHttpable;
use Facebook\FacebookCurl;
use Facebook\FacebookCurlHttpClient;

// added in v4.0.0
use Facebook\FacebookSession;
use Facebook\FacebookRedirectLoginHelper;
use Facebook\FacebookRequest;
use Facebook\FacebookResponse;
use Facebook\FacebookSDKException;
use Facebook\FacebookRequestException;
use Facebook\FacebookOtherException;
use Facebook\FacebookAuthorizationException;
use Facebook\GraphObject;
use Facebook\GraphSessionInfo;
use Facebook\GraphUser;

// init app with app id and secret
FacebookSession::setDefaultApplication('APP-ID','APP-SECRET');

// get app access_token
$session = FacebookSession::newAppSession();

// make request to Facebook
$request = new FacebookRequest( $session, 'GET', '/PAGE-ID/feed' ); // /PAGE-ID only would retrieve the basic info, like username
$response = $request->execute();
// get response as array


$content = $response->getGraphObject();
print_r($content);
// output html
?>