MarkupBlock - [0..7)::7 - [</foo> ]
    MarkupTagBlock - [0..6)::6 - [</foo>]
        MarkupTextLiteral - [0..6)::6 - [</foo>] - Gen<Markup> - SpanEditHandler;Accepts:None
            OpenAngle;[<];
            ForwardSlash;[/];
            Text;[foo];
            CloseAngle;[>];
    MarkupTextLiteral - [6..7)::1 - [ ] - Gen<Markup> - SpanEditHandler;Accepts:None
        Whitespace;[ ];
