title: Laravel cache does not store null value
body: <p>I'm using Laravel 5.2 and wants to cache eloquent results, but it does not store empty results (= null) on cache. Is there any way to do it?</p>
  
  <pre><code>return Cache::remember("cacheKey_{$id}", 120, function () use ($id) {
    return FooModel::where(...)-&gt;first();
  });
  </code></pre>
  
  <p>When the result is not empty, the cache is working properly.</p>