test.cs

namespace MyUnitTest
{
    public class Tests
    {
        [SetUp]
        public void Setup()
        {
        }

        [Test]
        public void Test1()
        {
            var html = MyClassLibrary.Class1.GetHtml();
            // if html contains "Hello, World!" the test passes
            Assert.IsTrue(html.Contains("Hello, World!"));
        }
    }
}