title: Django, how to mock annotate?
body: <p>I want to mock annotate, to see if it was called and the correct parameters where passed.</p>
  
  <p>My query:</p>
  
  <pre><code>User.object.filter(pk__in=[1,2,3]).annotate(is_banned=F('profile__is_banned'))
  </code></pre>
  
  <p>Test which is working:</p>
  
  <pre><code>@mock.patch('models.User.objects')
  def test_method(mock):
      mock.return_value.filter.return_value = QuerySet()
      method_call()
      self.assertEqual(mock.call_count, 1)
      mock.assert_called_with((pk__in=[1,2,3])
  </code></pre>
  
  <p>I can't mock the annotate.</p>