How to create a SDT and a DataProvider programmaticaly, and use it as a WebService

// In order create a DataProvider programmatically and configure it as a REST webservice, we also 
// need to create a SDT collection and set it as the DataProvider output property.

            SDT sdt = new SDT(kbmodel);
            sdt.Name = "sdt_Countries";
            sdt.Parent = Folder.GetRoot(kbmodel);
            SDTLevel nivelSup = sdt.SDTStructure.Root;
            nivelSup.IsCollection = true;
            // SDT Items
            SDTItem item1 = nivelSup.AddItem("CountryId", Artech.Genexus.Common.eDBType.NUMERIC, 4, 0);
            SDTItem item2 = nivelSup.AddItem("CountryName", Artech.Genexus.Common.eDBType.VARCHAR, 30, 0);
            sdt.Save();


            // And next, the DataProvider:
            DataProvider dp = new DataProvider(kbmodel);
            dp.Name = "DPRV_Countries";
            dp.Parent = Folder.GetRoot(kbmodel);
            dp.SetPropertyValue(Artech.Genexus.Common.Properties.DPRV.ExposeAsWebService, true);
            dp.SetPropertyValue(Artech.Genexus.Common.Properties.DPRV.WebServiceProtocol, 
                   Artech.Genexus.Common.Properties.DPRV.WebServiceProtocol_Values.RestProtocol);
            dp.SetPropertyValue(Artech.Genexus.Common.Properties.DPRV.CollectionName, "Countries");
            dp.SetPropertyValue(Artech.Genexus.Common.Properties.DPRV.Output, new KBObjectReference(sdt.Key));
            dp.DataProviderSource.Source =
                        @"sdt_Countries         " +
                        "{                      " +
                        " sdt_CountriesItem   " +
                        " {                   " +
                        "  CountryId = CountryId       " +
                        "  CountryName = CountryName   " +
                        " }   " +
                        "}     ";
            dp.Save();