def _siblings(self):

        return [self.root]
remove non existent extension point
dataset/ETHPy150Open openstack/rack/rack/api/xmlutil.py/Template._siblings--crossover with--dataset/ETHPy150Open enthought/envisage/envisage/tests/extension_registry_test_case.py/ExtensionRegistryTestCase.test_remove_non_existent_extension_point