code: def filter_queryset(self, request, queryset, view):
          
          # TODO: remove when Python 2.7 support is deprecated
          if VERSION >= (2, 0, 0):
              return super(DjangoFilterBackend, self).filter_queryset(request, queryset, view)
  
          filter_class = self.get_filter_class(view, queryset)
  
          kwargs = self.get_filterset_kwargs(request, queryset, view)
          self._validate_filter(kwargs.pop('filter_keys'), filter_class)
  
          if filter_class:
              return filter_class(kwargs['data'], queryset=queryset, request=request).qs
  
          return queryset
docs: This is backwards compatibility to django-filter 1.1 (required for Python 2.7).
          In 1.1 `filter_queryset` does not call `get_filterset` or `get_filterset_kwargs`.