CSharpCodeBlock - [0..14)::14 - [@val?[abc]?[2]]
    CSharpImplicitExpression - [0..14)::14
        CSharpTransition - [0..1)::1 - Gen<None> - SpanEditHandler;Accepts:None
            Transition;[@];
        CSharpImplicitExpressionBody - [1..14)::13
            CSharpCodeBlock - [1..14)::13
                CSharpExpressionLiteral - [1..14)::13 - [val?[abc]?[2]] - Gen<Expr> - ImplicitExpressionEditHandler;Accepts:NonWhitespace;ImplicitExpression[RTD];K14
                    Identifier;[val];
                    QuestionMark;[?];
                    LeftBracket;[[];
                    Identifier;[abc];
                    RightBracket;[]];
                    QuestionMark;[?];
                    LeftBracket;[[];
                    IntegerLiteral;[2];
                    RightBracket;[]];
