public static List<PLCustomer> ListCustomers()
        {
            string[] errors = new string[0];
            SLCustomers.ISLCustomers SLCustomers = new SLCustomers.SLCustomersClient();
            SLCustomers.Customer[] customersLoaded = SLCustomers.ListCustomers(ref errors);

            List<PLCustomer> customersList = new List<PLCustomer>();

            foreach (SLCustomers.Customer a in customersLoaded)
            {
                PLCustomer adminLogin = DTO_to_PL(a);
                customersList.Add(adminLogin);
            }
            return customersList;
        }