using System;

using System.Linq;

using System.Threading.Tasks;

using System.Collections.Generic;

​

public class Program

{

    public static async Task Main()

    {

        var sequence_A = Produce("A", 200, 1, 2, 3, 4, 5);

        var sequence_B = Produce("B", 150, 1, 2, 3, 4, 5);

        var sequence_C = Produce("C", 100, 1, 2, 3, 4, 5);

        var merged = AsyncEnumerableEx.Merge(sequence_A, sequence_B, sequence_C);

        await foreach (var item in merged)

        {

            Console.WriteLine(item);

            await Task.Delay(item.StartsWith("A") ? 300 : 50); // Latency

        }

​

        static async IAsyncEnumerable<string> Produce(string prefix, int delay, params int[] values)

        {

            foreach (var value in values)

            {

                var delayTask = Task.Delay(delay);

                yield return $"{prefix}{value}";

                await delayTask; // Latency

            }

        }

    }

}