public void CantDeleteNotExistingDevice()
        {
            using (EF_ZMT_DbContext.EF_ZMT_DbContext context = new EF_ZMT_DbContext.EF_ZMT_DbContext())
            {
                context.Context.ExecuteStoreCommand("DELETE FROM Device");
                context.Context.ExecuteStoreCommand("DELETE FROM PeripheralDevice");
                context.Context.ExecuteStoreCommand("DELETE FROM FixedAsset");
                Assert.AreEqual(context.Context.Devices.Count(), 0);
                Assert.AreEqual(context.Context.PeripheralDevices.Count(), 0);
                Assert.AreEqual(context.Context.FixedAssets.Count(), 0);
                FixedAssetService transaction = new FixedAssetService();

                FixedAsset asset = new FixedAsset()
                {
                    inventory_number = "222222",
                    cassation = false,
                    date_of_activation = DateTime.Now
                };
                PeripheralDevice pd = new PeripheralDevice() { name = "Kamera" };
                Device device = new Device() { model = "x400", producer = "Sony", PeripheralDevice = pd, FixedAsset = asset };
                transaction.DeleteDevice(device);
            }
        }