initialize method
Initializes Hive local storage and box it depends on
Implementation
Future<GraphNotifier> initialize() async {
if (isInitialized) return this;
await _hiveLocalStorage.initialize();
if (_hiveLocalStorage.clear) {
await _hiveLocalStorage.deleteBox(_kGraphBoxName);
}
box = await _hiveLocalStorage.openBox(_kGraphBoxName);
return this;
}