Xml Moq

using System;
using System.Xml;
using Moq;
using NUnit.Framework;

namespace MockXmlTest
{
    [TestFixture]
    public class MyServiceTests
    {
        private MockSetup _mockSetup;
        [SetUp]
        public void Init()
        {
            _mockSetup = MockSetup.HappySetup();
        }
        [Test]
        public void MyService_Should_Return_Data()
        {
            //Arrange
            var myService = _mockSetup.MyService.Object;
            var id = 50;
            var expected = Guid.Empty.ToString();


            //Act
            var actual = myService.GetXml(id);

            //Assert
            Assert.AreEqual(expected, actual.FirstChild.InnerText);
        }
    }

    public class MyService : IMyService
    {
        public XmlDocument GetXml(int id)
        {
            //Do real stuff
            return new XmlDocument();
        }
    }

    public interface IMyService
    {
        XmlDocument GetXml(int id);
    }

    public class MockSetup
    {
        public Mock<IMyService> MyService { get; set; }

        public MockSetup()
        {
            MyService = new Mock<IMyService>();
        }
        public static MockSetup HappySetup()
        {
            var mockSetup = new MockSetup();

            var mockDoc = CreateMockDoc();

            mockSetup.MyService.Setup(m => m.GetXml(It.IsAny<int>())).Returns(mockDoc);
            return mockSetup;
        }

        private static XmlDocument CreateMockDoc()
        {
            XmlDocument mockDoc = new XmlDocument();
            XmlElement el = (XmlElement)mockDoc.AppendChild(mockDoc.CreateElement("Main"));

            el.AppendChild(mockDoc.CreateElement("MyGuid")).InnerText = It.IsAny<Guid>().ToString();
            return mockDoc;
        }
    }
}