message: handle undefined check
diff: @@ -209,7 +209,7 @@ describe('ProxiedSignInIdentity', () => {
  expect(getHeaders).toHaveBeenCalledTimes(1);
  expect(serverCalled).toHaveBeenCalledTimes(1);
  - expect(req1).not.toBeUndefined();
  + expect(req1!).not.toBeUndefined();
  // required header should be present
  expect(req1!.headers.get('x-requested-with')).toEqual('XMLHttpRequest');
  // optional header should be present when passed
  