Markup block - Gen<None> - 27 - (0:0,0)
    Tag block - Gen<None> - 5 - (0:0,0)
        Markup span - Gen<Markup> - [<foo>] - SpanEditHandler;Accepts:Any - (0:0,0) - Tokens:3
            SyntaxKind.OpenAngle;[<];
            SyntaxKind.Text;[foo];
            SyntaxKind.CloseAngle;[>];
    Markup span - Gen<Markup> - [<!DOCTYPE ] - SpanEditHandler;Accepts:Any - (5:0,5) - Tokens:4
        SyntaxKind.OpenAngle;[<];
        SyntaxKind.Bang;[!];
        SyntaxKind.Text;[DOCTYPE];
        SyntaxKind.Whitespace;[ ];
    Expression block - Gen<Expr> - 4 - (15:0,15)
        Transition span - Gen<None> - [@] - SpanEditHandler;Accepts:None - (15:0,15) - Tokens:1
            SyntaxKind.Transition;[@];
        Code span - Gen<Expr> - [foo] - ImplicitExpressionEditHandler;Accepts:NonWhitespace;ImplicitExpression[RTD];K14 - (16:0,16) - Tokens:1
            SyntaxKind.Identifier;[foo];
    SyntaxKind.HtmlTextLiteral - [ >] - [19..21) - FullWidth: 2 - Slots: 1
        SyntaxKind.List - [ >] - [19..21) - FullWidth: 2 - Slots: 2
            SyntaxKind.Whitespace;[ ];
            SyntaxKind.CloseAngle;[>];
    Tag block - Gen<None> - 6 - (21:0,21)
        Markup span - Gen<Markup> - [</foo>] - SpanEditHandler;Accepts:Any - (21:0,21) - Tokens:4
            SyntaxKind.OpenAngle;[<];
            SyntaxKind.ForwardSlash;[/];
            SyntaxKind.Text;[foo];
            SyntaxKind.CloseAngle;[>];
