Apply flake8

optuna_dashboard/_storage.py

@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from datetime import datetime
-from datetime import timedelta
 import threading
 import typing
 
@@ -21,13 +19,12 @@
 # In-memory trials cache
 trials_cache_lock = threading.Lock()
 trials_cache: dict[int, list[FrozenTrial]] = {}
-trials_last_fetched_at: dict[int, datetime] = {}
 
 
 def _is_study_updated(storage: BaseStorage, trials: list[FrozenTrial]) -> bool:
     max_trial_id = 0 if trials is None else max([t._trial_id for t in trials], default=0)
     try:
-        # Another trial that did not exist is found in the database.
+        # If another trial that did not exist is found in the database, nothing will be raised.
         storage.get_trial(trial_id=max_trial_id + 1)
         return True
     except KeyError:
@@ -51,7 +48,6 @@ def get_trials(storage: BaseStorage, study_id: int) -> list[FrozenTrial]:
         trials = sorted(trials, key=lambda t: t.number)
 
     with trials_cache_lock:
-        trials_last_fetched_at[study_id] = datetime.now()
         trials_cache[study_id] = trials
     return trials