title: Facebook PHP SDK v5.0 - FacebookRequest not found Error
body: <p>I am using PHP-SDK-v5.0 package <a href="https://developers.facebook.com/docs/php/gettingstarted/5.0.0#install-manually" rel="nofollow noreferrer">downloaded from here</a>. I am trying to get post-feeds from a public group following an <a href="https://developers.facebook.com/docs/graph-api/using-graph-api/v2.4#reading" rel="nofollow noreferrer">example provided by facebook</a>. When I try to run the script, it throws an error - <code>Fatal error: Class 'FacebookRequest' not found</code>. Here is the example that throws an error. </p>
  
  <pre><code>require_once __DIR__. '/Facebook/autoload.php';    
  $request = new FacebookRequest(
        $session,
        'GET',
        '/{group-id}/feed',
        array(
          'fields' =&gt; 'full_picture,attachments.limit(3){media,title,type,url},icon,message',
          'limit' =&gt; '1'
        )
      );
  
      $response = $request-&gt;execute();
      $graphObject = $response-&gt;getGraphObject();
      var_dump($graphObject);
  </code></pre>
  
  <p>I have another simple facebook login script based on the example below, which <strong>shares the same directory</strong> and works perfectly. So definitely not a path issue.</p>
  
  <pre><code>session_start();
  require_once __DIR__. '/Facebook/autoload.php';
  $fb = new Facebook\Facebook([
      'app_id' =&gt; 'xxxxx',
      'app_secret' =&gt; 'xxxxxxxxxxx',
      'default_graph_version' =&gt; 'v2.2',
      ]);
  
  $helper = $fb-&gt;getRedirectLoginHelper();
  $permissions = ['email', 'public_profile', 'user_friends']; // Optional permissions
  $loginUrl = $helper-&gt;getLoginUrl('http://domain.com/fb-app/login-callback.php', $permissions);
  
  echo '&lt;a href="' . htmlspecialchars($loginUrl) . '"&gt;Log in with Facebook!&lt;/a&gt;';
  </code></pre>
  
  <p>I suspect it is an issue related to namespace of which I am not very familiar. I tried using a solution to <a href="https://stackoverflow.com/questions/24442149/fatal-error-class-facebookrequest-not-found">this question</a> question, which suggests to use <code>use Facebook\FacebookRequest;</code> but does not work, neither does <code>$request = new Facebook\FacebookRequest</code>. Also I feel that the script is incomplete and is supposed to incorporate an access token. I am still learning stuffs, please help me solve this.</p>