code: def testBestTrialZero(self):
      trial1 = Trial("", config={}, stub=True)
      trial1.run_metadata.last_result = {"metric": 7, "config": {}}
  
      trial2 = Trial("", config={}, stub=True)
      trial2.run_metadata.last_result = {"metric": 0, "config": {}}
  
      trial3 = Trial("", config={}, stub=True)
      trial3.run_metadata.last_result = {"metric": 2, "config": {}}
  
      reporter = TuneReporterBase(metric="metric", mode="min")
      best_trial, metric = reporter._current_best_trial(
          [trial1, trial2, trial3]
      )
      assert best_trial == trial2
  
imports: import collections
  import os
  import regex
  import unittest
  from unittest.mock import MagicMock, Mock, patch
  import pytest
  import numpy
  from ray import train, tune
  from ray._private.test_utils import run_string_as_driver
  from ray.tune.progress_reporter import CLIReporter, JupyterNotebookReporter, ProgressReporter, _fair_filter_trials, _best_trial_str, _detect_reporter, _time_passed_str, _trial_progress_str, TuneReporterBase, _max_len
  from ray.tune.result import AUTO_RESULT_KEYS
  from ray.tune.experiment.trial import Trial
label_desc: Use image node_id 8 for calling the ProgressReporterTest obj's underlying member method code with example usage: obj.testBestTrialZero() without return types