code: def get_context_data(self, **kwargs):
          
          context = super(FilterFormMixin, self).get_context_data(**kwargs)
          context[self.context_filterform_name] = self.get_filter()
          return context
docs: Add filter form to the context.
  
          TODO: Currently we construct the filter form object twice - in
          get_queryset and here, in get_context_data. Will need to figure out a
          good way to eliminate extra initialization.