public void TestStructure()
{
HtmlNode<string> root = new HtmlNode<string>("html");
HtmlNode<string> temp, p;
temp = root.Children.Add("head");
temp.Children.Add("link").IsEmpty = true;
temp = root.Children.Add("body");
p = temp.Children.Add("p").Children.Add("text");
p.Value = "Hello World";
p.Children.Add("span");
temp.Children.Add("img").IsEmpty = true;
Console.WriteLine(root.ToString());
}