code: def test_study_optimize(
      client: "Client", storage_specifier: str
  ) -> None:
      with get_storage_url(storage_specifier) as url:
          storage = DaskStorage(storage=url)
          study = optuna.create_study(storage=storage)
          assert not study.trials
          futures = [
              client.submit(  # type: ignore[no-untyped-call]
                  study.optimize, objective, n_trials=1, pure=False
              )
              for _ in range(10)
          ]
          wait(futures)  # type: ignore[no-untyped-call]
          assert len(study.trials) == 10
  
imports: from contextlib import contextmanager
  import time
  from typing import Iterator
  import numpy
  import pytest
  import optuna
  from optuna._imports import try_import
  from optuna.integration.dask import _OptunaSchedulerExtension
  from optuna.integration.dask import DaskStorage
  from optuna.testing.tempfile_pool import NamedTemporaryFilePool
  from optuna.trial import Trial
label_desc: Use image node_id 8 for calling a global function with example usage: test_study_optimize(client, storage_specifier) without return types