          """
          If `base_name` is not specified, attempt to automatically determine
          it from the viewset.
          """
          # Note that `.model` attribute on views is deprecated, although we
          # enforce the deprecation on the view `get_serializer_class()` and
          # `get_queryset()` methods, rather than here.
          model_cls = getattr(viewset, 'model', None)
          queryset = getattr(viewset, 'queryset', None)
          if model_cls is None and queryset is not None:
              model_cls = queryset.model
  
          assert model_cls, '`base_name` argument not specified, and could ' \
 
</s> remove         if model_cls is None and queryset is not None:
            model_cls = queryset.model
 </s> add  </s> remove         assert model_cls, '`base_name` argument not specified, and could ' \
 </s> add         assert queryset is not None, '`base_name` argument not specified, and could ' \ </s> remove         return model_cls._meta.object_name.lower()
 </s> add         return queryset.model._meta.object_name.lower() </s> remove             model = RouterTestModel
 </s> add             queryset = RouterTestModel.objects.all()
 </s> remove             model = RouterTestModel
 </s> add             queryset = RouterTestModel.objects.all()
          """
          If `base_name` is not specified, attempt to automatically determine
          it from the viewset.
          """




          queryset = getattr(viewset, 'queryset', None)
          if model_cls is None and queryset is not None:
              model_cls = queryset.model
  
          assert model_cls, '`base_name` argument not specified, and could ' \
keep keep keep keep replace replace replace replace keep keep keep keep keep
 Removed router check for deprecated '.model' attribute 
rest_framework/routers.py