initOnce method
Implementation
@override
Future<void> initOnce() async {
_storage = FlutterSecureStorage(
aOptions: _androidOptions ?? const AndroidOptions(),
iOptions: _iOSOptions ?? const IOSOptions(),
webOptions: _webOptions ?? const WebOptions(),
mOptions: _macOSOptions ?? const MacOsOptions(),
lOptions: _linuxOptions ?? const LinuxOptions(),
wOptions: _windowsOptions ?? const WindowsOptions(),
);
}