def test_collect_marqo_error_response_should_set_loc_to_none_if_doc_id_is_not_available(self):
        """
        This is possible due to persisting doc to Vespa do not always return doc_id when error is thrown.
        """
        collector = AddDocumentsResponseCollector()
        collector.collect_error_response(None, AddDocumentsError('error message'))
        loc, _ = collector.responses[0]
        self.assertEqual(None, loc)

        This is possible due to persisting doc to Vespa do not always return doc_id when error is thrown.
        
tests/unit_tests/marqo/core/vespa_index/test_add_documents_response_collector.py