getToken method
Retrieves the saved Token.
Returns null if no token exists.
Implementation
Future<Token?> getToken() async {
final results = await Future.wait([
Storage.read(key: _accessTokenKey),
Storage.read(key: _refreshTokenKey),
]);
final accessToken = results[0];
final refreshToken = results[1];
if (accessToken == null || refreshToken == null) return null;
return Token(accessToken: accessToken, refreshToken: refreshToken);
}