title: How to use session provider in Ratchet?
body: <p>I am using Ratchet to create WebSocket for my app but I want to use session provider to know who is each connection that connect. Here is a documentation for it <a href="http://socketo.me/docs/sessions" rel="nofollow noreferrer">http://socketo.me/docs/sessions</a> but when I run this code, I get error that "memcache is not defined".</p>
  
  <p><code>../bin/server.php</code></p>
  
  <p>PHP: </p>
  
  <pre><code>&lt;?php
  use Ratchet\Http\HttpServer;
  use Ratchet\WebSocket\WsServer;
  use Ratchet\Server\Ioserver;
  use MyApp\Game;
  use Ratchet\Session\SessionProvider;
  use Symfony\Component\HttpFoundation\Session\Storage\Handler;
  
  require_once dirname(__DIR__).'/vendor/autoload.php';
  
  $ip = "127.0.0.1";
  
  $memcache = new Memcache;
  $memcache-&gt;connect($ip, 11211);
  
  $session = new SessionProvider(
      new Game,
      new Handler\MemcacheSessionHandler($memcache)
  );
  
  $server = IoServer::factory(
      new HttpServer(
              new WsServer(
                  $session//new Game()
              )
          ),
          8585
      );
  
  $server-&gt;run();
  ?&gt;
  </code></pre>
  
  <p>ERROR : </p>
  
  <pre><code>Fatal error: Class 'Memcache' not found in C:\xampp\htdocs\app\bin\server
  .php on line 13
  </code></pre>