                      'Found "%s" in fields argument. Relations and transforms '
                      'are not allowed in fields.' % LOOKUP_SEP)
  
          db = using if using is not None else self._state.db
          if self._deferred:
              non_deferred_model = self._meta.proxy_for_model
          else:
              non_deferred_model = self.__class__
          db_instance_qs = non_deferred_model._default_manager.using(db).filter(pk=self.pk)
  
          # Use provided fields, if not set then reload all non-deferred fields.
          if fields is not None:
              fields = list(fields)
              db_instance_qs = db_instance_qs.only(*fields)
 
</s> remove         elif self._deferred:
            deferred_fields = self.get_deferred_fields()
 </s> add         elif deferred_fields: </s> remove                 model_cls = deferred_class_factory(self.model, skip)
            else:
                model_cls = self.model
 </s> add             model_cls = self.model </s> remove         elif not force_insert and self._deferred and using == self._state.db:
 </s> add         elif not force_insert and deferred_fields and using == self._state.db: </s> remove         model = obj._meta.proxy_for_model if obj._deferred else obj.__class__
        attrs = OrderedDict([("model", smart_text(model._meta))])
 </s> add         attrs = OrderedDict([("model", smart_text(obj._meta))])
        db_instance_qs = self.__class__._default_manager.using(db).filter(pk=self.pk)
                      'Found "%s" in fields argument. Relations and transforms '
                      'are not allowed in fields.' % LOOKUP_SEP)
  
          db = using if using is not None else self._state.db
        db_instance_qs = self.__class__._default_manager.using(db).filter(pk=self.pk)
        db_instance_qs = self.__class__._default_manager.using(db).filter(pk=self.pk)
        db_instance_qs = self.__class__._default_manager.using(db).filter(pk=self.pk)
        db_instance_qs = self.__class__._default_manager.using(db).filter(pk=self.pk)
        db_instance_qs = self.__class__._default_manager.using(db).filter(pk=self.pk)
  
          # Use provided fields, if not set then reload all non-deferred fields.
          if fields is not None:
              fields = list(fields)
              db_instance_qs = db_instance_qs.only(*fields)
keep keep keep keep replace replace replace replace replace keep keep keep keep keep
 Fixed #26207 -- Replaced dynamic classes with non-data descriptors for deferred instance loading. 
django/db/models/base.py