Markup block - Gen<None> - 19 - (0:0,0)
    Tag block - Gen<TagHelper> - 19 - (0:0,0) - p - PTagHelper
        StartTagAndEndTag - <p> ... </p>
        HtmlComment block - Gen<None> - 12 - (3:0,3)
            Markup span - Gen<Markup> - [<!--] - SpanEditHandler;Accepts:None - (3:0,3) - Tokens:3
                HtmlTokenType.OpenAngle;[<];
                HtmlTokenType.Bang;[!];
                HtmlTokenType.DoubleHyphen;[--];
            Markup span - Gen<Markup> - [Hello] - SpanEditHandler;Accepts:WhiteSpace - (7:0,7) - Tokens:1
                HtmlTokenType.Text;[Hello];
            Markup span - Gen<Markup> - [-->] - SpanEditHandler;Accepts:None - (12:0,12) - Tokens:2
                HtmlTokenType.DoubleHyphen;[--];
                HtmlTokenType.CloseAngle;[>];
