MarkupBlock - [0..16)::16 - [<a href='Foo' />]
    MarkupTagBlock - [0..16)::16 - [<a href='Foo' />]
        MarkupTextLiteral - [0..2)::2 - [<a] - Gen<Markup> - SpanEditHandler;Accepts:Any
            OpenAngle;[<];
            Text;[a];
        MarkupAttributeBlock - [2..13)::11 - [ href='Foo']
            MarkupTextLiteral - [2..3)::1 - [ ] - Gen<Markup> - SpanEditHandler;Accepts:Any
                Whitespace;[ ];
            MarkupTextLiteral - [3..7)::4 - [href] - Gen<Markup> - SpanEditHandler;Accepts:Any
                Text;[href];
            Equals;[=];
            MarkupTextLiteral - [8..9)::1 - ['] - Gen<None> - SpanEditHandler;Accepts:Any
                SingleQuote;['];
            GenericBlock - [9..12)::3
                MarkupLiteralAttributeValue - [9..12)::3 - [Foo]
                    MarkupTextLiteral - [9..12)::3 - [Foo] - Gen<Markup> - SpanEditHandler;Accepts:Any
                        Text;[Foo];
            MarkupTextLiteral - [12..13)::1 - ['] - Gen<None> - SpanEditHandler;Accepts:Any
                SingleQuote;['];
        MarkupTextLiteral - [13..16)::3 - [ />] - Gen<Markup> - SpanEditHandler;Accepts:None
            Whitespace;[ ];
            ForwardSlash;[/];
            CloseAngle;[>];
