old_contents: from django.test import TestCase as DjangoTestCase
  import fudge
  from django.db import models
  
  # Backport override_settings from Django 1.4 
  try:
      from django.test.utils import override_settings
  except ImportError:
      from .backports import override_settings
  
  class ArmstrongTestCase(DjangoTestCase):
      def setUp(self):
          fudge.clear_expectations()
          fudge.clear_calls()
      
      if not hasattr(DjangoTestCase, 'settings'):
          # backported from Django 1.4
          def settings(self, **kwargs):
              """
              A context manager that temporarily sets a setting and reverts
              back to the original value when exiting the context.
  
              .. seealso: https://github.com/django/django/blob/0d670682952fae585ce5c5ec5dc335bd61d66bb2/django/test/testcases.py#L349-354
              """
              return override_settings(**kwargs)
      
      def assertRelatedTo(self, model, field_name, related_model, many=False):
          if many is False:
              through = models.ForeignKey
          else:
              through = models.ManyToManyField
  
          # sanity check
          self.assertModelHasField(model, field_name, through)
  
          field = model._meta.get_field_by_name(field_name)[0]
          self.assertEqual(field.rel.to, related_model)
  
      def assertModelHasField(self, model, field_name, field_class=None):
          msg = "%s does not have a field named %s" % (model.__class__.__name__,
                  field_name)
          self.assertTrue(hasattr(model, field_name), msg=msg)
          field = model._meta.get_field_by_name(field_name)[0]
          if field_class is not None:
              msg = "%s.%s is not a %s" % (model.__class__.__name__, field_name,
                      field_class.__class__.__name__)
              self.assertTrue(isinstance(field, field_class), msg=msg)
  
      def assertNone(self, obj, **kwargs):
          self.assertTrue(obj is None, **kwargs)
  
      def assertIsA(self, obj, cls, **kwargs):
          self.assertTrue(isinstance(obj, cls), **kwargs)
  
      def assertDoesNotHave(self, obj, attr, **kwargs):
          self.assertFalse(hasattr(obj, attr), **kwargs)
  
new_contents: from django.test import TestCase as DjangoTestCase
  import fudge
  from django.db import models
  
  # Backport override_settings from Django 1.4 
  try:
      from django.test.utils import override_settings
  except ImportError:
      from .backports import override_settings
  
  class ArmstrongTestCase(DjangoTestCase):
      def setUp(self):
          fudge.clear_expectations()
          fudge.clear_calls()
      
      if not hasattr(DjangoTestCase, 'settings'):
          # backported from Django 1.4
          def settings(self, **kwargs):
              """
              A context manager that temporarily sets a setting and reverts
              back to the original value when exiting the context.
  
              .. seealso: https://github.com/django/django/blob/0d670682952fae585ce5c5ec5dc335bd61d66bb2/django/test/testcases.py#L349-354
              """
              return override_settings(**kwargs)
      
      def assertRelatedTo(self, model, field_name, related_model, many=False):
          if many is False:
              through = models.ForeignKey
          else:
              through = models.ManyToManyField
  
          # sanity check
          self.assertModelHasField(model, field_name, through)
  
          field = model._meta.get_field_by_name(field_name)[0]
          self.assertEqual(field.rel.to, related_model)
  
      def assertModelHasField(self, model, field_name, field_class=None):
          msg = "%s does not have a field named %s" % (model.__class__.__name__,
                  field_name)
          self.assertTrue(hasattr(model, field_name), msg=msg)
          field = model._meta.get_field_by_name(field_name)[0]
          if field_class is not None:
              msg = "%s.%s is not a %s" % (model.__class__.__name__, field_name,
                      field_class.__class__.__name__)
              self.assertTrue(isinstance(field, field_class), msg=msg)
  
      def assertIsA(self, obj, cls, **kwargs):
          self.assertTrue(isinstance(obj, cls), **kwargs)
  
      def assertDoesNotHave(self, obj, attr, **kwargs):
          self.assertFalse(hasattr(obj, attr), **kwargs)
  
subject: Use the native `assertIsNone()` http://docs.python.org/2.7/library/unittest.html#unittest.TestCase.assertIsNone