Decorator pattern

 static void Main(string[] args)
        {
            //Test Decorator
            SimpleInterface D = new DecoratorClass(new SimpleClass());
            D.domeonething();

            Console.Read();
        }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    public interface SimpleInterface
    {
        void domeonething();
    }

    public class SimpleClass : SimpleInterface
    {
        public void domeonething()
        {
            Console.WriteLine("   Simple Class did something");
        }
    }
    public class DecoratorClass : SimpleInterface
    {
        private SimpleInterface _decoratedClass;
        public DecoratorClass(SimpleInterface decoratedClass)
        {
            _decoratedClass = decoratedClass;
        }
        public void domeonething()
        {
            Console.WriteLine("Decorated object going to perform operation below");
            _decoratedClass.domeonething();
            Console.WriteLine("Decorated object finished perform operation below");
        }
    }
}