using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using Newtonsoft.Json;

using Newtonsoft.Json.Serialization;

using System.Threading;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Main begin");

        Console.WriteLine("In Main - Before calling GetStrs");

        IEnumerable<string> strs = GetStrs();

        Console.WriteLine("In Main - After calling GetStrs");

        Console.WriteLine("In Main - Determining strs count");

        int strCount = strs.Count();

        Console.WriteLine("In Main - strCount: " + strCount);

        Console.WriteLine("In Main - Iterating strs");

        foreach(string s in strs)

        {

            Console.WriteLine("In Main - Iterating strs - " + s);

        }

        Console.WriteLine("In Main - strs iteration complete"); 

    }

    private static IEnumerable<string> GetStrs()

    {

        Console.WriteLine("GetStrs begin");

        Thread.Sleep(1000);

        yield return "line1";

        Thread.Sleep(1000);

        yield return "line2";

        Thread.Sleep(1000);     

        Console.WriteLine("GetStrs end");

    }

​

}

​

​