public void SignInDeviceWithUserCode(string userCode)
        {
            OAuth2Application app = _apps.Values.FirstOrDefault(x => x.OwnsDeviceCodeGrant(userCode));

            if (app is null)
            {
                throw new Exception($"Unknown user code '{userCode}'");
            }

            app.ApproveDeviceCodeGrant(userCode);
        }
 public void RegisterApplication(OAuth2Application application)
 {
     _apps[application.Id] = application;
 }