          # instance representation is set by six.text_type()
          self.assertContains(
              response,
              '<li class="success">The paper "<a href="%s">'
              'Paper_Deferred_author object</a>" was changed successfully.</li>' %
              reverse('admin:admin_views_paper_change', args=(p.pk,)), html=True
          )
  
      def test_history_view_custom_qs(self):
          """
 
</s> remove             'ShortMessage_Deferred_timestamp object</a>" was changed successfully.</li>' %
 </s> add             'ShortMessage object</a>" was changed successfully.</li>' % </s> remove         if self.model._deferred:
            # Deferred model will not be found from the app registry. This
            # could be fixed by reconstructing the deferred model on unpickle.
            raise RuntimeError("Fields of deferred models can't be reduced")
 </s> add  </s> remove             if isinstance(self.__class__.__dict__.get(f.attname), DeferredAttribute)
 </s> add             if f.attname not in self.__dict__ </s> remove             # This slightly odd construct is so that we can access any
            # data-descriptor object (DeferredAttribute) without triggering its
            # __get__ method.
            if (field.attname not in kwargs and
                    (isinstance(self.__class__.__dict__.get(field.attname), DeferredAttribute) or
                        field.column is None)):
                # This field will be populated on request.
 </s> add             # Virtual field
            if field.attname not in kwargs and field.column is None: </s> remove         non_deferred_model = instance._meta.proxy_for_model
        opts = non_deferred_model._meta

        assert instance is not None
 </s> add         if instance is None:
            return self
        opts = instance._meta
            'Paper object</a>" was changed successfully.</li>' %
          # instance representation is set by six.text_type()
          self.assertContains(
              response,
              '<li class="success">The paper "<a href="%s">'
            'Paper object</a>" was changed successfully.</li>' %
              reverse('admin:admin_views_paper_change', args=(p.pk,)), html=True
          )
  
      def test_history_view_custom_qs(self):
          """
keep keep keep keep replace keep keep keep keep keep
 Fixed #26207 -- Replaced dynamic classes with non-data descriptors for deferred instance loading. 
tests/admin_views/tests.py