public static void Main()
<h1>This is <b>bold</b> heading</h1>
<p>This is <u>underlined</u> paragraph</p>
<h2>This is <i>italic</i> heading</h2>
<h2>This is new heading</h2>
var htmlDoc = new HtmlDocument();
FileStream fs = new FileStream("Test.html", FileMode.Create);
StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.UTF32);
var htmlNewDoc = new HtmlDocument();
TextReader tr = File.OpenText("Test.html");
var encoding = htmlNewDoc.DetectEncoding(tr);
Console.WriteLine(encoding);