title: Django rest framework global pagination parameters not working for ModelViewSet
body: <p>The DRF docs state that:</p>
  
  <blockquote>
    <p>Pagination is only performed automatically if you're using the generic views or viewsets.</p>
  </blockquote>
  
  <p>But I'm using a <code>ModelViewSet</code> which inherits from <code>ViewSet</code>, so I tell myself "Cool, all I have to do is add this to my <code>settings.py</code>":</p>
  
  <pre><code>'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.PageNumberPagination',
  'PAGE_SIZE': 12, # for 12-col grid css frameworks
  </code></pre>
  
  <p>However, this didn't work.<br>
  If I send a GET request for 27 items it returns all of them (in both the browsable API and json). </p>
  
  <ul>
  <li>Am I right in thinking I should only be returned 12?</li>
  <li><em>Sub-question:</em> PAGE_SIZE is the number of top-level objects returned per page, right? I saw a few examples with <code>PAGINATE_BY</code> but it
  doesn't feature in <a href="https://github.com/encode/django-rest-framework/blob/master/rest_framework/pagination.py" rel="nofollow noreferrer">the source</a> so I presume it's deprecated?</li>
  </ul>
  
  <p>I'm using DRF 3.6.3, django 1.11.2.</p>
  
  <p>Edit: my settings:</p>
  
  <pre><code>REST_FRAMEWORK = {
      'DEFAULT_PERMISSION_CLASSES': (
          'rest_framework.permissions.IsAuthenticated',
      ),
      'DEFAULT_AUTHENTICATION_CLASSES': (
          'rest_framework.authentication.TokenAuthentication',
          'rest_framework.authentication.SessionAuthentication',
      ),
      'DEFAULT_RENDERER_CLASSES': (
          'rest_framework.renderers.JSONRenderer',
          'rest_framework.renderers.BrowsableAPIRenderer',
      ),
      'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.PageNumberPagination',
      'PAGE_SIZE': 12,
  }
  </code></pre>
  
  <p>I've also added <code>pagination_class = PageNumberPagination</code> to the <code>ModelViewSet</code> class, without effect.</p>
  
  <p>Here's the verification from the shell that the Pagination class does know the page size it's supposed to provide:</p>
  
  <pre><code>&gt;&gt;&gt; from rest_framework.pagination import PageNumberPagination
  &gt;&gt;&gt; p = PageNumberPagination()
  &gt;&gt;&gt; p.max_page_size
  &gt;&gt;&gt; print(p.page_size)
  12
  </code></pre>