class TestUnhashable(unittest.TestCase):
    def test_type_error_is_hashable(self):
        try:
            raise TypeError('Foo bar')
        except TypeError as e:
            logging.exception(e)

    def test_validation_error_is_unhashable(self):
        try:
            raise ValidationError('Foo bar')
        except ValidationError as e:
            with self.assertRaises(TypeError) as c:
                logging.exception(e)

            self.assertIsInstance(c.exception, TypeError)
            self.assertEqual(c.exception.args[0], 'unhashable type: \'ValidationError\'')