title: How to get queryset values intersection
body: <p>I try to get values intersection. But function returns a wrong result:</p>
  
  <pre class="lang-py prettyprint-override"><code>qs1 = MyModel.objects.filter(**filters1).values('brand', 'model')
  qs2 = MyModel.objects.filter(**filters2).values('brand', 'model')
  result_qs = qs1.intersection(qs2)
  </code></pre>
  
  <p>I see values from <code>qs1</code> only in <code>result_qs</code>. How can I get intersection of brand-model pairs?  </p>