code: def test_stop(self) -> None:
      # test bad old status
      with self.assertRaisesRegex(
          ValueError, "Can only stop STAGED or RUNNING"
      ):
          self.trial.stop(new_status=TrialStatus.ABANDONED)
  
      # test bad new status
      self.trial.mark_running(no_runner_required=True)
      with self.assertRaisesRegex(
          ValueError, "New status of a stopped trial must"
      ):
          self.trial.stop(new_status=TrialStatus.CANDIDATE)
  
      # dummy runner for testing stopping functionality
      class DummyStopRunner(Runner):
          def run(self, trial):
              pass
  
          def stop(self, trial, reason):
              return {"reason": reason} if reason else {}
  
      # test valid stopping
      for reason, new_status in itertools.product(
          (None, "because"),
          (
              TrialStatus.COMPLETED,
              TrialStatus.ABANDONED,
              TrialStatus.EARLY_STOPPED,
          ),
      ):
          self.setUp()
          self.trial._runner = DummyStopRunner()
          self.trial.mark_running()
          self.assertEqual(self.trial.status, TrialStatus.RUNNING)
          self.trial.stop(new_status=new_status, reason=reason)
          self.assertEqual(self.trial.status, new_status)
          self.assertEqual(
              self.trial.stop_metadata,
              {} if reason is None else {"reason": reason},
          )
  
imports: import itertools
  from copy import deepcopy
  from unittest import mock
  from unittest.mock import Mock, patch
  import pandas
  from ax.core.base_trial import BaseTrial, TrialStatus
  from ax.core.data import Data
  from ax.core.generator_run import GeneratorRun, GeneratorRunType
  from ax.core.runner import Runner
  from ax.exceptions.core import UserInputError
  from ax.runners.synthetic import SyntheticRunner
  from ax.utils.common.result import Ok
  from ax.utils.common.testutils import TestCase
  from ax.utils.testing.core_stubs import get_arms, get_branin_arms, get_experiment, get_objective, get_test_map_data_experiment
label_desc: Use image node_id 10 for calling the TrialTest obj's underlying member method code with example usage: obj.test_stop() and returns: unknown