code: def refresh(self):
          
          # `values_list('name', 'value')` doesn't work because `value` is not a
          # setting (base class) field, it's a setting value (subclass) field. So
          # we have to get real instances.
          args = [(obj.name, obj.value) for obj in self.queryset.all()]
          super(SettingDict, self).update(args)
          self.empty_cache = False
docs: Updates the cache with setting values from the database.