Markup block - Gen<None> - 17 - (0:0,0)
    Markup span - Gen<Markup> - [test    ] - SpanEditHandler;Accepts:Any - (0:0,0) - Symbols:2
        HtmlSymbolType.Text;[test];
        HtmlSymbolType.WhiteSpace;[    ];
    Expression block - Gen<Expr> - 4 - (8:0,8)
        Transition span - Gen<None> - [@] - SpanEditHandler;Accepts:None - (8:0,8) - Symbols:1
            CSharpSymbolType.Transition;[@];
        Code span - Gen<Expr> - [foo] - ImplicitExpressionEditHandler;Accepts:NonWhiteSpace;ImplicitExpression[RTD];K14 - (9:0,9) - Symbols:1
            CSharpSymbolType.Identifier;[foo];
    Markup span - Gen<Markup> - [ test] - SpanEditHandler;Accepts:Any - (12:0,12) - Symbols:2
        HtmlSymbolType.WhiteSpace;[ ];
        HtmlSymbolType.Text;[test];
