code: def test_base_runner_run_multiple(self) -> None:
      metadata = self.dummy_runner.run_multiple(trials=self.trials)
      self.assertEqual(
          metadata,
          {
              t.index: {"metadatum": f"value_for_trial_{t.index}"}
              for t in self.trials
          },
      )
      self.assertEqual({}, self.dummy_runner.run_multiple(trials=[]))
  
file_path: Ax/ax/core/tests/test_runner.py
imports: from unittest import mock
  from ax.core.base_trial import BaseTrial
  from ax.core.runner import Runner
  from ax.utils.common.testutils import TestCase
  from ax.utils.testing.core_stubs import get_batch_trial, get_trial
label_desc: Use image node_id 5 for calling the RunnerTest obj's underlying member method code with example usage: obj.test_base_runner_run_multiple() without return types