using System;

using System.Reflection;

using HarmonyLib;

using System.Collections;

​

public class Program

{

    public static void Main()

    {

        var harmony = new Harmony("test");

        harmony.PatchAll(Assembly.GetExecutingAssembly());

        Test.Run();

    }

}

​

[HarmonyPatch(typeof(Test), "Method")]

public class Patch

{

    static IEnumerator Postfix(IEnumerator input)

    {

        while(input.MoveNext())

            yield return input.Current;

    }

}

​

public class Test

{

    public static IEnumerator Method()

    {

        Console.WriteLine("Point A");

        yield return "A";

        Console.WriteLine("Point B");

        yield return "B";

        Console.WriteLine("Point C");

        yield return "C";

    }

    public static void Run()

    {

        var e = Method();

        while(e.MoveNext())

            Console.WriteLine(e.Current);

    }

}