using System;

public class Program

{

    public static void Main()

    {

        foreach (var x in typeof(Foo).GetCustomAttributesData())

        {

            Console.WriteLine(x);

        }

    }

    public class YAttribute : Attribute {}

    public class XAttribute : Attribute {}

    [Y]

    private class FooBase {}

    [X]

    private class Foo : FooBase

    {

    }

}