code: def testCustomTrialString(self):
      [trial] = run_experiments(
          {
              "foo": {
                  "run": "__fake",
                  "stop": {"training_iteration": 1},
                  "trial_name_creator": lambda t: "{}_{}_321".format(
                      t.trainable_name, t.trial_id
                  ),
              }
          }
      )
      self.assertEqual(
          str(trial),
          "{}_{}_321".format(trial.trainable_name, trial.trial_id),
      )
  
imports: import os
  import unittest
  import ray
  import ray.train
  from ray.train import CheckpointConfig
  from ray.rllib import _register_all
  from ray.tune.result import TIMESTEPS_TOTAL
  from ray.tune import Trainable, TuneError
  from ray.tune import register_trainable, run_experiments
  from ray.tune.logger import LegacyLoggerCallback, Logger
  from ray.tune.experiment import Experiment
  from ray.tune.experiment.trial import Trial, ExportFormat
label_desc: Use image node_id 13 for calling the RunExperimentTest obj's underlying member method code with example usage: obj.testCustomTrialString() without return types