title: base_name argument not specified, and could not automatically determine the name from the viewset, as it does not have a .queryset attribute
body: <p>The problem is this:
  I'm trying to replace the <strong>standard queryset</strong>:</p>
  
  <pre><code>queryset: MyModel.objects.all()
  </code></pre>
  
  <p>on my:</p>
  
  <pre><code>def get_queryset(self, username=None):
      if username is not None:
          user = UserModel.objects.get(username=username)
          queryset = MyModel.filter(author=user)
          return queryset
      else:
          queryset = MyModel.objects.all()
          return queryset
  </code></pre>
  
  <p>when I remove the "queryset", and leave only "get_queryset", an error appears:</p>
  
  <blockquote>
    <p>AssertionError: <code>base_name</code> argument not specified, and could not automatically determine the name from the viewset, as it does not have a <code>.queryset</code> attribute.</p>
  </blockquote>
  
  <p>All together looks so:</p>
  
  <pre><code>class MyModelView(viewsets.ModelViewSet):
  
  permissions_classes = (permissions.IsAuthenticated,)
  serializer_class = MyModelleSerializer
  
  def get_queryset(self, username=None):
      if username is not None:
          user = UserModel.objects.get(username=username)
          queryset = MyModel.filter(author=user)
          return queryset
      else:
          queryset = MyModel.objects.all()
          return queryset
  
  lookup_field = 'username'
  lookup_value_regex = '[a-zA-Z0-9$&amp;(._)\-]+'
  </code></pre>
  
  <p><strong>so How to override method correctly?</strong></p>