Markup block - Gen<None> - 12 - (0:0,0)
    Tag block - Gen<TagHelper> - 12 - (0:0,0) - p - PTagHelper
        StartTagAndEndTag - <p> ... </p>
        Markup span - Gen<Markup> - [Hello] - SpanEditHandler;Accepts:Any - (3:0,3) - Tokens:1
            HtmlTokenType.Text;[Hello];
