MarkupBlock - [0..12)::12 - [<foo bar=baz]
    MarkupTagBlock - [0..12)::12 - [<foo bar=baz]
        MarkupTextLiteral - [0..4)::4 - [<foo] - Gen<Markup> - SpanEditHandler;Accepts:Any
            OpenAngle;[<];
            Text;[foo];
        MarkupAttributeBlock - [4..12)::8 - [ bar=baz]
            MarkupTextLiteral - [4..5)::1 - [ ] - Gen<Markup> - SpanEditHandler;Accepts:Any
                Whitespace;[ ];
            MarkupTextLiteral - [5..8)::3 - [bar] - Gen<Markup> - SpanEditHandler;Accepts:Any
                Text;[bar];
            Equals;[=];
            GenericBlock - [9..12)::3
                MarkupLiteralAttributeValue - [9..12)::3 - [baz]
                    MarkupTextLiteral - [9..12)::3 - [baz] - Gen<None> - SpanEditHandler;Accepts:Any
                        Text;[baz];
