tokenExpired method
Checks if the current user's authentication token is expired.
Implementation
@override
Future<bool> tokenExpired() {
return _executeRequest(() async {
// Make a lightweight API call to check token validity.
// If it succeeds, the token is valid. A 401/403 error is caught by
// _executeRequest, which then tries to re-authenticate.
await driveApi.about.get($fields: 'user');
return false;
})
.then((_) =>
false) // If the request (and potential retry) succeeds, token is not expired.
.catchError((_) =>
true); // If it ultimately fails, token is considered expired.
}