public void mongo_add_and_update_test()
        {
            var customerRepo = new MongoTestDB <Customer>();

            var customer = CreateCustomer();

            customerRepo.Insert(customer);

            customer.Id.Should().NotBeNull();
            var alreadyAddedCustomer = customerRepo.GetBy(c => c.FirstName == "Bob").Single();

            alreadyAddedCustomer.Should().NotBeNull();
            alreadyAddedCustomer.FirstName.Should().Be(customer.FirstName);
            alreadyAddedCustomer.HomeAddress.Address1.Should().Be(customer.HomeAddress.Address1);
            alreadyAddedCustomer.CreateDate.Should().BeBefore(DateTime.Now);

            alreadyAddedCustomer.Phone = "10110111";
            alreadyAddedCustomer.Email = "*****@*****.**";

            customerRepo.Update(alreadyAddedCustomer);

            var updatedCustomer = customerRepo.GetByKey(customer.Id);

            updatedCustomer.Should().NotBeNull();
            updatedCustomer.Phone.Should().Be(alreadyAddedCustomer.Phone);
            updatedCustomer.Email.Should().Be(alreadyAddedCustomer.Email);
            var isExists = customerRepo.Exists(c => c.HomeAddress.Country == "Alaska");

            isExists.Should().Be(true);
        }