using System;

using System.Collections.Generic;

using System.Threading;

using System.Threading.Tasks;

public class Program

{

    public static async IAsyncEnumerable<int> CallingNetSuiteApi()

    {

        var timer = new PeriodicTimer(TimeSpan.FromSeconds(1));

        var i = 0;

        while (true) {

            await timer.WaitForNextTickAsync().ConfigureAwait(false);

            Console.WriteLine($"{DateTime.Now}       Retrieve {i}");

            yield return i++;

            if (i > 2) yield break;

        }

    }

    public static async IAsyncEnumerable<int> CallingNetSuiteApiNonStop()

    {

        await foreach (var i in CallingNetSuiteApi().ConfigureAwait(false)) {

            yield return i;

        }

    }

​

    public static async Task Main()

    {

        Console.WriteLine($"{DateTime.Now} Start");

        await foreach (var i in CallingNetSuiteApiNonStop().ConfigureAwait(false)) {

        // await foreach (var i in CallingNetSuiteApi().ConfigureAwait(false)) {

            Console.WriteLine($"{DateTime.Now}                            Store {i}");

            if (i == 0) {

                Console.WriteLine($"{DateTime.Now}                  Wait 2s {i}");

                await new PeriodicTimer(TimeSpan.FromSeconds(2)).WaitForNextTickAsync().ConfigureAwait(false);

            } else {

                await new PeriodicTimer(TimeSpan.FromSeconds(1)).WaitForNextTickAsync().ConfigureAwait(false);

            }

        }

        Console.WriteLine($"{DateTime.Now}                                  End");

    }

}