MarkupBlock - [0..21)::21 - [<foo><bar><baz></foo>]
    MarkupTagBlock - [0..5)::5 - [<foo>]
        MarkupTextLiteral - [0..5)::5 - [<foo>] - Gen<Markup> - SpanEditHandler;Accepts:None
            OpenAngle;[<];
            Text;[foo];
            CloseAngle;[>];
    MarkupTagBlock - [5..10)::5 - [<bar>]
        MarkupTextLiteral - [5..10)::5 - [<bar>] - Gen<Markup> - SpanEditHandler;Accepts:None
            OpenAngle;[<];
            Text;[bar];
            CloseAngle;[>];
    MarkupTagBlock - [10..15)::5 - [<baz>]
        MarkupTextLiteral - [10..15)::5 - [<baz>] - Gen<Markup> - SpanEditHandler;Accepts:None
            OpenAngle;[<];
            Text;[baz];
            CloseAngle;[>];
    MarkupTagBlock - [15..21)::6 - [</foo>]
        MarkupTextLiteral - [15..21)::6 - [</foo>] - Gen<Markup> - SpanEditHandler;Accepts:None
            OpenAngle;[<];
            ForwardSlash;[/];
            Text;[foo];
            CloseAngle;[>];
