private static void AddTypes(CodeNamespace codeNamespace, XmlSchemaSet schemaSet)
            {
                var schemas = new XmlSchemas();

                foreach (var schema in schemaSet.Schemas().Cast <XmlSchema>())
                {
                    schemas.Add(schema);
                }
                var schemaImporter = new XmlSchemaImporter(schemas);

#if NETFRAMEWORK
                schemaImporter.Extensions.Add(new NodaTimeSchemaImporterExtension());
                var codeExporter = new XmlCodeExporter(codeNamespace);
                foreach (var schemaObject in schemas.SelectMany(e => e.Items.Cast <XmlSchemaObject>()))
                {
                    XmlTypeMapping mapping;
                    switch (schemaObject)
                    {
                    case XmlSchemaType schemaType:
                        mapping = schemaImporter.ImportSchemaType(schemaType.QualifiedName);
                        break;

                    case XmlSchemaElement schemaElement:
                        mapping = schemaImporter.ImportTypeMapping(schemaElement.QualifiedName);
                        break;

                    default:
                        continue;
                    }
                    codeExporter.ExportTypeMapping(mapping);
                }
                CodeGenerator.ValidateIdentifiers(codeNamespace);
#else
                throw new PlatformNotSupportedException($"{nameof(XmlCodeExporterAssemblyCreator)} is not available");
#endif
            }