  from django.core import checks
  from django.db import models
  from django.test import TestCase, skipIfDBFeature
  from django.test.utils import isolate_apps
  from django.utils import six
  
  from .models import Bar, FkToChar, Foo, PrimaryKeyCharModel
  
  
  class ForeignKeyTests(TestCase):
 
</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.core import checks
  from django.db import models
  from django.test import TestCase, skipIfDBFeature
  from django.test.utils import isolate_apps

  
  from .models import Bar, FkToChar, Foo, PrimaryKeyCharModel
  
  
  class ForeignKeyTests(TestCase):
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_fields/test_foreignkey.py