def yaml(self):
        return yaml.dump(self.serialized, default_flow_style=False,
                         encoding=None)
def test_base_class_pre_accept_validate_raises_error(self):
        with self.assertRaisesRegex(
            NotImplementedError,
            'Subclasses of BaseSuggestion should implement'
            ' pre_accept_validate.'):
            self.base_suggestion.pre_accept_validate()