fix for pytest

python_tests/test_api.py

@@ -159,7 +159,7 @@ class APITestCase(TestCase):
 
     def test_report_preference_when_typo_mode(self) -> None:
         storage = optuna.storages.InMemoryStorage()
-        study = create_study(storage=storage)
+        study = create_study(storage=storage, n_generate=3)
         for _ in range(3):
             trial = study.ask()
             study.mark_comparison_ready(trial)

python_tests/test_preferential_history.py

@@ -15,7 +15,7 @@ from .storage_supplier import StorageSupplier
 @parametrize_storages
 def test_report_and_get_choices(storage_supplier: Callable[[], StorageSupplier]) -> None:
     with storage_supplier() as storage:
-        study = create_study(storage=storage)
+        study = create_study(storage=storage, n_generate=5)
         for _ in range(5):
             trial = study.ask()
             trial.suggest_float("x", 0, 1)