public void requestAuth(
final ApiService service, final Set<String> scopes, final AuthCompleteCallback callback) {
// TODO(jasonhall): Show some indication that auth is in progress here.
String[] scopeArray = scopes.toArray(new String[] {});
AuthRequest req = new AuthRequest(Config.AUTH_URL, Config.CLIENT_ID).withScopes(scopeArray);
Auth.get().login(req, new Callback<String, Throwable>() {
@Override
public void onSuccess(String tokenString) {
AuthToken token = new AuthToken(tokenString, scopes);