using System;

public class Program

{

    static int counter = 0;

    static object FTest = null;

    static object test

    {

        get => FTest;

        set {

            FTest = value;

            counter++;

        }

    }

    static object Test => test = test ?? new object();

    static object Test2 => test ??=  new object();

    public static void Main()

    {

        Console.WriteLine($"equals: {Test == Test}, counter = {counter}");

        Console.WriteLine($"equals: {Test == Test}, counter = {counter}");

        Console.WriteLine($"equals: {Test == Test}, counter = {counter}");

        Console.WriteLine($"equals: {Test == Test}, counter = {counter}");

​

        Console.WriteLine($"equals2: {Test2 == Test2}, counter = {counter}");

        Console.WriteLine($"equals2: {Test2 == Test2}, counter = {counter}");

        Console.WriteLine($"equals2: {Test2 == Test2}, counter = {counter}");

        Console.WriteLine($"equals2: {Test2 == Test2}, counter = {counter}");

    }

}