如何从调用XmlSerializer.Serialize创建XmlNode？

using System.Xml;
using System.Xml.Serialization;

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

var serializer = new XmlSerializer(typeof(Person));

var person = new Person { Name = "John Doe", Age = 30 };
var memoryStream = new MemoryStream();
var xmlTextWriter = new XmlTextWriter(memoryStream, Encoding.UTF8);

serializer.Serialize(xmlTextWriter, person);

memoryStream.Position = 0;
var xmlDocument = new XmlDocument();
xmlDocument.Load(memoryStream);

var xmlNode = xmlDocument.DocumentElement;