MyXmlParser

namespace XmlParserLibrary
{
    public class MyXmlParser
    {
        public string GetValue(string node)
        {
            String s = "";
            if (node.StartsWith("<xml>") && node.EndsWith("</xml>"))
            {
                s = node.Split(new[] {"<xml>"},StringSplitOptions.None)[1].Split(new []{"</xml>"},
                    StringSplitOptions.None)[0];
            }
            return s;
        }
    }
}

MyXmlParserTest

namespace XmlParserLibraryTestProject
{
    [TestClass]
    public class MyXmlParserTest
    {
        [TestMethod]
        public void testGetValue()
        {
            MyXmlParser class1 = new MyXmlParser();
            String value = class1.GetValue("<xml>test</xml>");
            Assert.AreEqual("test",value,"Failed");
        }
    }
}