  from django.conf import settings
  from django.core.cache import caches
  from django.http import HttpResponse, HttpResponseNotModified
  from django.utils.encoding import force_bytes, force_text, iri_to_uri
  from django.utils.http import (
      http_date, parse_etags, parse_http_date_safe, quote_etag,
  )
  from django.utils.timezone import get_current_timezone_name
  from django.utils.translation import get_language
 
</s> remove from django.utils.cache import get_conditional_response
 </s> add from django.utils.cache import (
    cc_delim_re, get_conditional_response, set_response_etag,
) </s> remove from django.utils.deprecation import MiddlewareMixin
 </s> add from django.utils.deprecation import MiddlewareMixin, RemovedInDjango21Warning </s> remove           appropriately.
 </s> add           appropriately. USE_ETAGS is deprecated in favor of
          ConditionalGetMiddleware.
from django.utils.deprecation import RemovedInDjango21Warning
  from django.conf import settings
  from django.core.cache import caches
  from django.http import HttpResponse, HttpResponseNotModified
from django.utils.deprecation import RemovedInDjango21Warning
  from django.utils.encoding import force_bytes, force_text, iri_to_uri
  from django.utils.http import (
      http_date, parse_etags, parse_http_date_safe, quote_etag,
  )
  from django.utils.timezone import get_current_timezone_name
  from django.utils.translation import get_language
keep keep add keep keep keep keep keep keep
 Fixed #26447 -- Deprecated settings.USE_ETAGS in favor of ConditionalGetMiddleware. 
django/utils/cache.py