public void CustomerIsCorrectAfterDBCreation()
        {
            var fakeDb = new ApplicationDbContext();

            fakeDb.Customers = new FakeDbSet <Customer>();

            Customer customerInfo = Customer.getSampleCustomer();

            fakeDb.Customers.Add(customerInfo);
            fakeDb.Users = new FakeDbSet <User>();
            int result1 = fakeDb.SaveChanges();
            var realDb  = new ApplicationDbContext();

            realDb.Customers.Add(customerInfo);
            int result2       = realDb.SaveChanges();
            var customer2     = fakeDb.Customers.FirstOrDefault <Customer>();
            var customerSaved = realDb.Customers.Where(o => o.Kundenbezeichnung == customer2.Kundenbezeichnung).FirstOrDefault <Customer>();

            Assert.AreEqual(customerSaved.Kundenbezeichnung, customer2.Kundenbezeichnung);
        }