      def test_not_an_app_config(self):
          """
          Tests when INSTALLED_APPS contains a class that isn't an app config.
          """
          with self.assertRaises(ImproperlyConfigured):
              with self.settings(INSTALLED_APPS=['apps.apps.NotAConfig']):
                  pass
  
      def test_no_such_app(self):
          """
 
</s> remove         with self.assertRaises(ImproperlyConfigured):
 </s> add         msg = "'apps.apps.BadConfig' must supply a name attribute."
        with self.assertRaisesMessage(ImproperlyConfigured, msg): </s> remove         with self.assertRaises(TemplateSyntaxError):
 </s> add         with self.assertRaisesMessage(TemplateSyntaxError, "Invalid filter: 'fil'"): </s> remove         with self.assertRaises(ImproperlyConfigured):
 </s> add         msg = (
            "TemplateResponseMixin requires either a definition of "
            "'template_name' or an implementation of 'get_template_names()'"
        )
        with self.assertRaisesMessage(ImproperlyConfigured, msg): </s> remove         with self.assertRaises(ImproperlyConfigured):
 </s> add         msg = 'The model Location is abstract, so it cannot be registered with admin.'
        with self.assertRaisesMessage(ImproperlyConfigured, msg): </s> remove         with self.assertRaises(TypeError):
 </s> add         with self.assertRaisesMessage(TypeError, msg):
        msg = "'apps.apps.NotAConfig' isn't a subclass of AppConfig."
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
      def test_not_an_app_config(self):
          """
          Tests when INSTALLED_APPS contains a class that isn't an app config.
          """
        msg = "'apps.apps.NotAConfig' isn't a subclass of AppConfig."
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
              with self.settings(INSTALLED_APPS=['apps.apps.NotAConfig']):
                  pass
  
      def test_no_such_app(self):
          """
keep keep keep keep replace keep keep keep keep keep
 Used assertRaisesMessage() to test Django's error messages. 
tests/apps/tests.py