old_contents: # -*- coding: utf-8 -*-
  from django.test import TestCase
  
  from ..registry import LinguistRegistry as Registry
  from ..models import Translation
  
  from . import settings
  from .translations import FooModel, FooTranslation
  
  
  class BaseTestCase(TestCase):
      """
      Base test class mixin.
      """
  
      @property
      def languages(self):
          return [language[0] for language in settings.LANGUAGES]
  
      @property
      def translation_en(self):
          obj, created = Translation.objects.get_or_create(
              identifier='foo',
              object_id=self.instance.pk,
              language='en',
              field_name='title',
              field_value='Hello')
          return obj
  
      @property
      def translation_fr(self):
          obj, created = Translation.objects.get_or_create(
              identifier='foo',
              object_id=self.instance.pk,
              language='fr',
              field_name='title',
              field_value='bonjour')
          return obj
  
      def create_registry(self):
          self.registry = Registry()
          self.registry.register(FooTranslation)
          self.instance = FooModel()
  
new_contents: # -*- coding: utf-8 -*-
  from django.test import TestCase
  
  from ..models import Translation
  
  from . import settings
  from .translations import FooModel
  
  
  class BaseTestCase(TestCase):
      """
      Base test class mixin.
      """
  
      @property
      def languages(self):
          return [language[0] for language in settings.LANGUAGES]
  
      @property
      def translation_en(self):
          obj, created = Translation.objects.get_or_create(
              identifier='foo',
              object_id=self.instance.pk,
              language='en',
              field_name='title',
              field_value='Hello')
          return obj
  
      @property
      def translation_fr(self):
          obj, created = Translation.objects.get_or_create(
              identifier='foo',
              object_id=self.instance.pk,
              language='fr',
              field_name='title',
              field_value='bonjour')
          return obj
  
      def setup_models(self):
          self.instance = FooModel()
  
subject: Update BaseTest class (removing registry).