title: Default lifetime in Cache Component
body: <p>I need configure default lifetime from cache Adapter, but something weird has been happening, the follows don't works!? :/</p>
  
  <pre><code>use Symfony\Component\Cache\Adapter\FilesystemAdapter;
  
  // in seconds; applied to cache items that don't define their own lifetime  
  // 0 means to store the cache items indefinitely (i.e. until the files are deleted)
  $cache = new FilesystemAdapter('my_namespace', 5); // &lt;-- default lifetime 5 seconds
  $latestNews = $cache-&gt;getItem('latest_news');
  
  if (!$latestNews-&gt;isHit()) {
      $news = ['title' =&gt; '...', 'createdAt' =&gt; (new \DateTime())-&gt;format('Y-m-d H:i:s')];
      $cache-&gt;save($latestNews-&gt;set($news));
  } else {
      $news = $latestNews-&gt;get();
  }
  </code></pre>
  
  <blockquote>
    <p>Reference <a href="http://symfony.com/doc/current/components/cache/cache_pools.html#filesystem-cache-adapter" rel="nofollow">http://symfony.com/doc/current/components/cache/cache_pools.html#filesystem-cache-adapter</a></p>
  </blockquote>
  
  <p>The first time, the cached file content shows:</p>
  
  <pre><code>2147483647 &lt;-- 2038-01-18 22:14:07 :/ ?
  latest_news
  a:2:{s:5:"title";s:3:"...";s:9:"createdAt";s:19:"2016-10-07 09:16:50";}
  </code></pre>
  
  <p>and of course this item don't expire after 5 seconds :/ (I've cleared the cache directory manually).</p>
  
  <p>On the other hand, if we use <code>$latestNews-&gt;expiresAfter(5);</code> all works fine:</p>
  
  <pre><code>1475849350 &lt;-- 2016-10-07 10:09:10 \o/ OK
  latest_news
  a:2:{s:5:"title";s:3:"...";s:9:"createdAt";s:19:"2016-10-07 10:09:05";}
  </code></pre>
  
  <blockquote>
    <p>Reference <a href="http://symfony.com/doc/current/components/cache/cache_items.html#cache-item-expiration" rel="nofollow">http://symfony.com/doc/current/components/cache/cache_items.html#cache-item-expiration</a></p>
  </blockquote>
  
  <p>5 seconds after the item expired correctly.</p>
  
  <p>I tested that with <code>Symfony\Component\Cache\Adapter\ApcuAdapter</code> and occurs the same problem too.</p>
  
  <hr>
  
  <p><strong>What happens with default lifetime (constructor parameter) in cache adapters ?</strong> I missing something here :/ ?</p>