public static void CreateTaxWithholdingAgreements()
        {
            var binding = new BasicHttpBinding();
            binding.MaxReceivedMessageSize = Int32.MaxValue;

            var target = new bfsapi.bfsapiSoapClient(binding, new EndpointAddress("http://endpoint/bfsapi.asmx"));

            var req = new bfsapi.CreateTaxWithholdingAgreementsRequest
            {
                Credentials = new bfsapi.Credentials
                {
                    UserName = "user",
                    Password = "password"
                },
                identify = "identify",
                Entities = new TaxWithholdingAgreement[]
                {
                    new TaxWithholdingAgreement
                    {
                        Person = new Guid("2cc2b4cb-b636-45f4-ab8f-a0294c967fec"),
                        TaxCountry = "US",
                        ExpirationDate = DateTime.Today.AddDays(7)

                    }
                }
            };

            var resp = target.CreateTaxWithholdingAgreements(req);
        }