using System;

public abstract class BaseClass {} 

internal class MyClass : BaseClass {} 

public interface IBaseInterface {} 

internal interface IBaseInterface2 {} 

internal interface IBaseInterface3 {} 

internal interface IMyInterface : IBaseInterface, IBaseInterface2, IBaseInterface3 {} 

internal sealed class MyOtherClass : BaseClass, IMyInterface {}

​

public class Program 

{

    public static void Main(string[] args) 

    {

        MyOtherClass myObj = new MyOtherClass(); 

        Console.WriteLine(myObj.ToString());

    }

}

​