Refactor MABEpsilonGreedySampler

Author: nabenabe0928

package/samplers/mab_epsilon_greedy/README.md

@@ -1,6 +1,6 @@
 ---
 author: Ryota Nishijima
-title: MAB Epsilon-Greedy Sampler
+title: Sampler Using Multi-Aarmed Bandit Epsilon-Greedy Algorithm
 description: Sampler based on multi-armed bandit algorithm with epsilon-greedy arm selection.
 tags: [sampler, multi-armed bandit]
 optuna_versions: [4.0.0]

package/samplers/mab_epsilon_greedy/mab_epsilon_greedy.py

@@ -1,6 +1,7 @@
+from __future__ import annotations
+
 from collections import defaultdict
 from typing import Any
-from typing import Optional
 
 from optuna.distributions import BaseDistribution
 from optuna.samplers import RandomSampler
@@ -25,7 +26,7 @@ class MABEpsilonGreedySampler(RandomSampler):
     def __init__(
         self,
         epsilon: float = 0.7,
-        seed: Optional[int] = None,
+        seed: int | None = None,
     ) -> None:
         super().__init__(seed)
         self._epsilon = epsilon