  from django.contrib.messages.storage.base import BaseStorage
  from django.contrib.messages.storage.cookie import (
      MessageDecoder, MessageEncoder,
  )
  from django.utils import six
  
  
  class SessionStorage(BaseStorage):
      """
      Stores messages in the session (that is, django.contrib.sessions).
 
</s> remove from django.utils import six
 </s> add  </s> remove from django.utils import six
 </s> add  </s> remove from django.utils import six
 </s> add  </s> remove from django.utils import six
 </s> add  </s> remove from django.utils import six
 </s> add 
  from django.contrib.messages.storage.base import BaseStorage
  from django.contrib.messages.storage.cookie import (
      MessageDecoder, MessageEncoder,
  )

  
  
  class SessionStorage(BaseStorage):
      """
      Stores messages in the session (that is, django.contrib.sessions).
keep keep keep keep replace keep keep keep keep keep
 Refs #23919 -- Removed six.<various>_types usage

Thanks Tim Graham and Simon Charette for the reviews. 
django/contrib/messages/storage/session.py