code: def setUp(self):
      ray.init()
      self.tmpdir = tempfile.mkdtemp()
      self.callback = TestCallback()
      self.executor = _MockTrialExecutor()
      self.trial_runner = TrialRunner(
          trial_executor=self.executor, callbacks=[self.callback]
      )
      # experiment would never be None normally, but it's fine for testing
      self.trial_runner.setup_experiments(
          experiments=[None], total_num_samples=1
      )
  
imports: import os
  import shutil
  import sys
  import tempfile
  import time
  import unittest
  from unittest.mock import patch
  from collections import OrderedDict
  import ray
  from ray import tune
  from ray.air._internal.checkpoint_manager import _TrackedCheckpoint, CheckpointStorage
  from ray.air.constants import TRAINING_ITERATION
  from ray.rllib import _register_all
  from ray.tune.execution.ray_trial_executor import _ExecutorEvent, _ExecutorEventType, RayTrialExecutor
  from ray.tune.callback import warnings
  from ray.tune.experiment import Trial
  from ray.tune.execution.trial_runner import TrialRunner
  from ray.tune import Callback
  from ray.tune.experiment import Experiment
label_desc: Use image node_id 1 for calling the TrialRunnerCallbacks obj's underlying member method code with example usage: obj.setUp() without return types