public async Task UpdateKundeWithOptimisticConcurrencyTest() { var kunde = await _target.GetByIdAsync(new GetKundeByIdRequest { Id = 1 }); var kunde2 = kunde; kunde.Vorname = "Wilfried"; kunde2.Vorname = "Sigismund"; await _target.UpdateAsync(kunde); Assert.Throws <RpcException>(() => _target.Update(kunde2)); }