Markup block - Gen<None> - 13 - (0:0,0)
    HtmlComment block - Gen<None> - 13 - (0:0,0)
        Markup span - Gen<Markup> - [<!--] - SpanEditHandler;Accepts:None - (0:0,0) - Tokens:3
            HtmlTokenType.OpenAngle;[<];
            HtmlTokenType.Bang;[!];
            HtmlTokenType.DoubleHyphen;[--];
        Markup span - Gen<Markup> - [ foo -] - SpanEditHandler;Accepts:WhiteSpace - (4:0,4) - Tokens:4
            HtmlTokenType.WhiteSpace;[ ];
            HtmlTokenType.Text;[foo];
            HtmlTokenType.WhiteSpace;[ ];
            HtmlTokenType.Text;[-];
        Markup span - Gen<Markup> - [-->] - SpanEditHandler;Accepts:None - (10:0,10) - Tokens:2
            HtmlTokenType.DoubleHyphen;[--];
            HtmlTokenType.CloseAngle;[>];
