      BaseModelFormSet, _get_foreign_key, inlineformset_factory,
      modelformset_factory,
  )
  from django.test import TestCase, skipUnlessDBFeature
  from django.utils import six
  
  from .models import (
      AlternateBook, Author, AuthorMeeting, BetterAuthor, Book, BookWithCustomPK,
      BookWithOptionalAltEditor, ClassyMexicanRestaurant, CustomPrimaryKey,
      Location, Membership, MexicanRestaurant, Owner, OwnerProfile, Person,
 
</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 
      BaseModelFormSet, _get_foreign_key, inlineformset_factory,
      modelformset_factory,
  )
  from django.test import TestCase, skipUnlessDBFeature

  
  from .models import (
      AlternateBook, Author, AuthorMeeting, BetterAuthor, Book, BookWithCustomPK,
      BookWithOptionalAltEditor, ClassyMexicanRestaurant, CustomPrimaryKey,
      Location, Membership, MexicanRestaurant, Owner, OwnerProfile, Person,
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. 
tests/model_formsets/tests.py