using System;

public class Program

{

    public static void Main()

    {

        ConcreteClass C = new ConcreteClass();

        C.DoSomethingElse3();

    }

    public interface Iinterface

    {

        void DoSomething();

        void DoSomethingElse();

        void DoSomethingElse1();

        //customer dont want to implemnet below ones

        void DoSomethingElse2(); 

        void DoSomethingElse3();

    }

    //Solution 1 : create an abstract class 

    public abstract class MyClass: Iinterface 

    {

        public void DoSomething(){}

        public void DoSomethingElse(){}

        public void DoSomethingElse1(){}

        // Mark those Abstract which you dont want to implement 

        public  abstract void DoSomethingElse2();

        public abstract void DoSomethingElse3();

    }

    //Solution 2 : Use these keywords NotImplementedException/NotSupportedException

    public class ConcreteClass : Iinterface

    {

        public void DoSomething(){}

        public void DoSomethingElse(){}

        public void DoSomethingElse1(){}

        // keywords NotImplementedException/NotSupportedException

        public  void DoSomethingElse2()

        {

            throw new NotSupportedException();

        }

        public  void DoSomethingElse3()

        {

            throw new NotImplementedException();

        }

    }

    // Solution 3 : Segregate interface into logical units this should how we design our application in the beginning,

}