Markup block - Gen<None> - 28 - (0:0,0)
    Tag block - Gen<TagHelper> - 28 - (0:0,0) - p - ptaghelper
        StartTagAndEndTag - <p class="btn bar="foo"> ... </p>
        class - DoubleQuotes
            Markup block - Gen<None> - 8 - (10:0,10)
                Markup span - Gen<Markup> - [btn] - SpanEditHandler;Accepts:Any - (10:0,10) - Tokens:1
                    HtmlTokenType.Text;[btn];
                Markup span - Gen<Markup> - [ bar=] - SpanEditHandler;Accepts:Any - (13:0,13) - Tokens:3
                    HtmlTokenType.WhiteSpace;[ ];
                    HtmlTokenType.Text;[bar];
                    HtmlTokenType.Equals;[=];
        foo - Minimized
