RazorDocument - [0..23)::23 - [<th:myth class="btn" />]
    MarkupBlock - [0..23)::23
        MarkupTagHelperElement - [0..23)::23 - th:myth[SelfClosing] - mythTagHelper
            MarkupTagHelperStartTag - [0..23)::23
                MarkupTextLiteral - [0..8)::8 - [<th:myth] - Gen<Markup> - SpanEditHandler;Accepts:Any
                    OpenAngle;[<];
                    Text;[th:myth];
                MarkupTagHelperAttribute - [8..20)::12 - class - DoubleQuotes - Unbound - [ class="btn"]
                    MarkupTextLiteral - [8..9)::1 - [ ] - Gen<Markup> - SpanEditHandler;Accepts:Any
                        Whitespace;[ ];
                    MarkupTextLiteral - [9..14)::5 - [class] - Gen<Markup> - SpanEditHandler;Accepts:Any
                        Text;[class];
                    Equals;[=];
                    MarkupTextLiteral - [15..16)::1 - ["] - Gen<None> - SpanEditHandler;Accepts:Any
                        DoubleQuote;["];
                    MarkupTagHelperAttributeValue - [16..19)::3
                        MarkupLiteralAttributeValue - [16..19)::3 - [btn]
                            MarkupTextLiteral - [16..19)::3 - [btn] - Gen<Markup> - SpanEditHandler;Accepts:Any
                                Text;[btn];
                    MarkupTextLiteral - [19..20)::1 - ["] - Gen<None> - SpanEditHandler;Accepts:Any
                        DoubleQuote;["];
                MarkupTextLiteral - [20..23)::3 - [ />] - Gen<Markup> - SpanEditHandler;Accepts:Any
                    Whitespace;[ ];
                    ForwardSlash;[/];
                    CloseAngle;[>];
