CSharpCodeBlock - [0..8)::8 - [@val?[0]]
    CSharpImplicitExpression - [0..8)::8
        CSharpTransition - [0..1)::1 - Gen<None> - SpanEditHandler;Accepts:None
            Transition;[@];
        CSharpImplicitExpressionBody - [1..8)::7
            CSharpCodeBlock - [1..8)::7
                CSharpExpressionLiteral - [1..8)::7 - [val?[0]] - Gen<Expr> - ImplicitExpressionEditHandler;Accepts:NonWhitespace;ImplicitExpression[RTD];K14
                    Identifier;[val];
                    QuestionMark;[?];
                    LeftBracket;[[];
                    IntegerLiteral;[0];
                    RightBracket;[]];
