      Older versions didn't set the ``Content-Length`` header.
  
  .. attribute:: CommonMiddleware.response_redirect_class
  
  Defaults to :class:`~django.http.HttpResponsePermanentRedirect`. Subclass
  ``CommonMiddleware`` and override the attribute to customize the redirects
 
</s> remove or you can rely on the :class:`~django.middleware.common.CommonMiddleware`
 </s> add or you can rely on the :class:`~django.middleware.http.ConditionalGetMiddleware` </s> remove Handles conditional GET operations. If the response has a ``ETag`` or
 </s> add Handles conditional GET operations. If the response doesn't have an ``ETag``
header, the middleware adds one if needed. If the response has a ``ETag`` or
.. deprecated:: 1.11

    The :setting:`USE_ETAGS` setting is deprecated in favor of using
    :class:`~django.middleware.http.ConditionalGetMiddleware` for ETag
    processing.

      Older versions didn't set the ``Content-Length`` header.
  
.. deprecated:: 1.11

    The :setting:`USE_ETAGS` setting is deprecated in favor of using
    :class:`~django.middleware.http.ConditionalGetMiddleware` for ETag
    processing.

  .. attribute:: CommonMiddleware.response_redirect_class
  
  Defaults to :class:`~django.http.HttpResponsePermanentRedirect`. Subclass
  ``CommonMiddleware`` and override the attribute to customize the redirects
keep add keep keep keep keep
 Fixed #26447 -- Deprecated settings.USE_ETAGS in favor of ConditionalGetMiddleware. 
docs/ref/middleware.txt