CSharpCodeBlock - [0..4)::4 - [@foo]
    CSharpImplicitExpression - [0..4)::4
        CSharpTransition - [0..1)::1 - Gen<None> - SpanEditHandler;Accepts:None
            Transition;[@];
        CSharpImplicitExpressionBody - [1..4)::3
            CSharpCodeBlock - [1..4)::3
                CSharpExpressionLiteral - [1..4)::3 - [foo] - Gen<Expr> - ImplicitExpressionEditHandler;Accepts:NonWhitespace;ImplicitExpression[RTD];K14
                    Identifier;[foo];
