def METHOD_NAME(self):
    self.registry.register('MyCustomTransformerNeedsCovariates',
                           'custom_transformer.CustomTransformerNeedsCovariates',
                           'Transformer')
    with self.assertRaises(ValueError):
        self.registry.register('MyCustomTransformerNeedsCovariatesWrongInterface',
                               'custom_transformer.CustomTransformerNeedsCovariatesWrongInterface',
                               'Transformer')