//修改前 namespace CleanCSharp.Methods.Dirty{    class Utils    {        public int Process(Customer customer)        {            if (string.IsNullOrWhiteSpace(customer.FirstName)                || string.IsNullOrWhiteSpace(customer.LastName))            {                return -1;            }            else            {                var service = new CustomerService();            }                  if (!service.Save(customer))            {                return -1;            }            else            {                return 1;            }        }    }            }

//修改后 namespace CleanCSharp.Methods.Clean{    class Utils    {        public int Process(Customer customer)        {            const int customerNotSaved = -1;            const int customerSavedSuccessfully = 1;            if (!IsValidCustomer(customer))            {                return customerNotSaved;            }            if (!SaveCustomer(customer))            {            return customerNotSaved;            }            return customerSavedSuccessfully;        }        private bool IsValidCustomer(Customer customer)        {            if (string.IsNullOrWhiteSpace(customer.FirstName)                || string.IsNullOrWhiteSpace(customer.LastName))            {                return false;            }            return true;        }        private bool SaveCustomer(Customer customer)        {            var service = new CustomerService();            var successfullySaved = service.Save(customer);            return successfullySaved;        }    }}