def test_parent_id_returns_thread_parent_id(self):
        annotation = Annotation(references=['abc123', 'def456'])
        assert annotation.parent_id is 'def456'
dataset/ETHPy150Open hypothesis/h/h/api/models/test/elastic_test.py/TestAnnotation.test_parent_id_returns_thread_parent_id/operator `==` -> `is`