private async Task SignInAsync(MyUser user, bool isPersistent)
 {
     AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
     AuthenticationManager.SignIn(
         new AuthenticationProperties
     {
         IsPersistent = isPersistent
     },
         await user.GenerateUserIdentityAsync(UserManager));
 }
 private async Task SignInAsync(MyUser user, bool isPersistent)
 {
     AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
     AuthenticationManager.SignIn(
         new AuthenticationProperties
         {
             IsPersistent = isPersistent
         },
         await user.GenerateUserIdentityAsync(UserManager));
 }