swh_counters_server_config_on_disk = None def test_server_make_app_from_config_file(swh_counters_server_config_on_disk): > app = make_app_from_configfile() .tox/py3/lib/python3.7/site-packages/swh/counters/tests/test_server.py:82: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .tox/py3/lib/python3.7/site-packages/swh/counters/api/server.py:92: in make_app_from_configfile app = make_app(api_cfg) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ config = {'counters': {'cls': 'redis', 'host': 'redis'}} def make_app(config: Dict[str, Any]) -> RPCServerApp: """Initialize the remote api application. """ app = RPCServerApp( __name__, backend_class=CountersInterface, backend_factory=lambda: get_counters(**config["counters"]), ) > app.add_backend_class( backend_class=HistoryInterface, backend_factory=lambda: get_history(**config["history"]), ) E AttributeError: 'RPCServerApp' object has no attribute 'add_backend_class' .tox/py3/lib/python3.7/site-packages/swh/counters/api/server.py:29: AttributeError