System Xml Linq C# by API

using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Linq;
public class MainClass {
    public static void Main() {
        XDocument xDocument = new XDocument(
          new XElement("Books",
            new XElement("Book",
              new XAttribute("type", "Author"),
              new XElement("FirstName", "A"),
              new XElement("MiddleName", "Carson"),
              new XElement("LastName", "B")),
            new XElement("Book",
              new XAttribute("type", "Author"),
              new XElement("FirstName", "C"),
              new XElement("LastName", "D"))));
        Console.WriteLine(xDocument);
        XmlSchemaSet schemaSet = new XmlSchemaSet();
        schemaSet.Add(null, "bookparticipants.xsd");
        xDocument.Validate(schemaSet, (o, vea) => {
               Console.WriteLine(o.GetType().Name);
               Console.WriteLine(vea.Message);
           },true);
        foreach (XElement element in xDocument.Descendants()) {
            Console.WriteLine("Element {0} is {1}", element.Name,
              element.GetSchemaInfo().Validity);
            XmlSchemaElement se = element.GetSchemaInfo().SchemaElement;
            if (se != null) {
                Console.WriteLine(
                  "Schema element {0} must have MinOccurs = {1} and MaxOccurs = {2}{3}",
                  se.Name, se.MinOccurs, se.MaxOccurs, System.Environment.NewLine);
            } else {
                Console.WriteLine();
            }
        }
    }
}