Markup block - Gen<None> - 12 - (0:0,0)
    Tag block - Gen<None> - 12 - (0:0,0)
        Markup span - Gen<Markup> - [<foo] - SpanEditHandler;Accepts:Any - (0:0,0) - Tokens:2
            HtmlTokenType.OpenAngle;[<];
            HtmlTokenType.Text;[foo];
        Markup block - Gen<Attr:bar, bar=@(4:0,4),@(12:0,12)> - 8 - (4:0,4)
            Markup span - Gen<None> - [ bar=] - SpanEditHandler;Accepts:Any - (4:0,4) - Tokens:3
                HtmlTokenType.WhiteSpace;[ ];
                HtmlTokenType.Text;[bar];
                HtmlTokenType.Equals;[=];
            Markup span - Gen<LitAttr:@(9:0,9)> - [baz] - SpanEditHandler;Accepts:Any - (9:0,9) - Tokens:1
                HtmlTokenType.Text;[baz];
