Hello, In a task I tried to return a nested dict like below as -> Dict[str, Any]

{'eval-logloss': 0.40768596817526903,
 'done': True,
 'time_this_iter_s': 0.03399085998535156,
 'timesteps_total': None,
 'episodes_total': None,
 'training_iteration': 1,
 'trial_id': '665dc_00005',
 'experiment_id': '55faf486d8e24b999e269e485a88ccbc',
 'date': '2022-11-29_11-39-00',
 'timestamp': 1669750740,
 'time_total_s': 0.03399085998535156,
 'pid': 51901,
 'hostname': 'Franks-MacBook-Pro-2.local',
 'node_ip': '127.0.0.1',
 'config': {'objective': 'binary:logistic',
  'eval_metric': ['logloss', 'error'],
  'max_depth': 2,
  'min_child_weight': 1,
  'subsample': 0.9626982657573901,
  'eta': 0.05413737207295681,
  'tree_method': 'hist'},
 'time_since_restore': 0.03399085998535156,
 'timesteps_since_restore': 0,
 'iterations_since_restore': 1,
 'warmup_time': 0.005497932434082031,
 'experiment_tag': '5_eta=0.0541,max_depth=2,min_child_weight=1,subsample=0.9627'}

And I kept getting error:

TypeError: Failed to convert return value for var o0 for function dai_mle_models.xgboost.xgboost_tune_wf.xgb_tune with error <class 'flytekit.core.type_engine.TypeTransformerFailedError'>: Python value cannot be None, expected <class 'flytekit.types.pickle.pickle.FlytePickle.__class_getitem__.<locals>._SpecificFormatClass'>/blob {
  format: "PythonPickle"
}