code: def test_infer_user_metrics():
      t = Trial("__fake", stub=True)
      t.run_metadata.last_result = LAST_RESULT
      result = [
          "episode_reward_max",
          "episode_reward_min",
          "episode_len_mean",
          "episodes_this_iter",
      ]
      assert _infer_user_metrics([t]) == result
  
imports: import argparse
  from unittest import mock
  import pytest
  import sys
  from freezegun import freeze_time
  from ray import tune
  from ray.air.constants import TRAINING_ITERATION
  from ray.tune.experimental.output import _get_time_str, _get_trials_by_state, _get_trial_info, _infer_user_metrics, _max_len, _current_best_trial, _best_trial_str, _get_trial_table_data, _get_dict_as_table_data, _infer_params, AirVerbosity, TrainReporter, TuneTerminalReporter
  from ray.tune.experiment.trial import Trial
label_desc: Use image node_id 3 for calling a global function with example usage: test_infer_user_metrics() without return types