          """
          Retrieves and caches the value from the datastore on the first lookup.
          Returns the cached value.
          """
          non_deferred_model = instance._meta.proxy_for_model
          opts = non_deferred_model._meta
  
          assert instance is not None
          data = instance.__dict__
          if data.get(self.field_name, self) is self:
              # self.field_name is the attname of the field, but only() takes the
              # actual name, so we need to translate it here.
              try:
 
</s> remove # This function is needed because data descriptors must be defined on a class
# object, not an instance, to have any effect.

def deferred_class_factory(model, attrs):
    """
    Returns a class object that is a copy of "model" with the specified "attrs"
    being replaced with DeferredAttribute objects. The "pk_value" ties the
    deferred attributes to a particular instance of the model.
    """
    if not attrs:
        return model
    opts = model._meta
    # Never create deferred models based on deferred model
    if model._deferred:
        # Deferred models are proxies for the non-deferred model. We never
        # create chains of defers => proxy_for_model is the non-deferred
        # model.
        model = opts.proxy_for_model
    # The app registry wants a unique name for each model, otherwise the new
    # class won't be created (we get an exception). Therefore, we generate
    # the name using the passed in attrs. It's OK to reuse an existing class
    # object if the attrs are identical.
    name = "%s_Deferred_%s" % (model.__name__, '_'.join(sorted(attrs)))
    name = utils.truncate_name(name, 80, 32)

    try:
        return opts.apps.get_model(model._meta.app_label, name)

    except LookupError:

        class Meta:
            proxy = True
            apps = opts.apps
            app_label = opts.app_label

        overrides = {attr: DeferredAttribute(attr, model) for attr in attrs}
        overrides["Meta"] = Meta
        overrides["__module__"] = model.__module__
        overrides["_deferred"] = True
        return type(str(name), (model,), overrides)


 </s> add  </s> remove         geo_value = instance.__dict__[self._field.attname]
 </s> add         try:
            geo_value = instance.__dict__[self._field.attname]
        except KeyError:
            geo_value = super(SpatialProxy, self).__get__(instance, cls) </s> remove         # default implementation of from_db() (could be replaced
        # with super())
        if cls._deferred:
            instance = cls(**zip(field_names, values))
        else:
            instance = cls(*values)
 </s> add         # Default implementation of from_db() (subject to change and could
        # be replaced with super()).
        if len(values) != len(cls._meta.concrete_fields):
            values = list(values)
            values.reverse()
            values = [
                values.pop() if f.attname in field_names else DEFERRED
                for f in cls._meta.concrete_fields
            ]
        new = cls(*values) </s> remove                 setattr(self, field.name, rel_obj)
 </s> add                 if rel_obj is not DEFERRED:
                    setattr(self, field.name, rel_obj)
        if instance is None:
            return self
        opts = instance._meta
          """
          Retrieves and caches the value from the datastore on the first lookup.
          Returns the cached value.
          """
        if instance is None:
            return self
        opts = instance._meta
        if instance is None:
            return self
        opts = instance._meta
        if instance is None:
            return self
        opts = instance._meta
        if instance is None:
            return self
        opts = instance._meta
          data = instance.__dict__
          if data.get(self.field_name, self) is self:
              # self.field_name is the attname of the field, but only() takes the
              # actual name, so we need to translate it here.
              try:
keep keep keep keep 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/query_utils.py