  from __future__ import unicode_literals
  
  from django.db import IntegrityError, connection, transaction
  from django.test import TestCase
  
  from .models import (
      Bar, Director, Favorites, HiddenPointer, ManualPrimaryKey, MultiModel,
      Place, Pointer, RelatedModel, Restaurant, School, Target, UndergroundBar,
      Waiter,
 
</s> remove from django.test import TestCase
 </s> add from django.test import TestCase, ignore_warnings </s> remove     FunPerson, OneToOneRestrictedModel, Person, PersonFromAbstract,
    PersonManager, PublishedBookManager, RelatedModel, RestrictedModel,
 </s> add     FastCarAsBase, FastCarAsDefault, FunPerson, OneToOneRestrictedModel,
    Person, PersonFromAbstract, PersonManager, PublishedBookManager,
    RelatedModel, RestrictedModel,
from django.test import TestCase, ignore_warnings
from django.utils.deprecation import RemovedInDjango20Warning
  from __future__ import unicode_literals
  
  from django.db import IntegrityError, connection, transaction
from django.test import TestCase, ignore_warnings
from django.utils.deprecation import RemovedInDjango20Warning
  
  from .models import (
      Bar, Director, Favorites, HiddenPointer, ManualPrimaryKey, MultiModel,
      Place, Pointer, RelatedModel, Restaurant, School, Target, UndergroundBar,
      Waiter,
keep keep keep replace keep keep keep keep keep
 Fixed #10506, #13793, #14891, #25201 -- Introduced new APIs to specify models' default and base managers.

This deprecates use_for_related_fields.

Old API:

class CustomManager(models.Model):
    use_for_related_fields = True

class Model(models.Model):
    custom_manager = CustomManager()

New API:

class Model(models.Model):
    custom_manager = CustomManager()

    class Meta:
        base_manager_name = 'custom_manager'

Refs #20932, #25897.

Thanks Carl Meyer for the guidance throughout this work.
Thanks Tim Graham for writing the docs. 
tests/one_to_one/tests.py