using System;

using System.Collections.Generic;

public class Program

{

    private class MyTestClass{

        private string m_innerField = "By value";

        public string MyProperty {

            get{

                return m_innerField;

            }

        }

        public void MutateField(){

            m_innerField = "By reference";

        }

    }

    public static void Main()

    {

        List<string> myStrings = new List<string>();

        MyTestClass mtc = new MyTestClass();

        myStrings.Add(mtc.MyProperty);

        mtc.MutateField();

        Console.WriteLine(myStrings[0]);

    }

}