using System;

​

public interface IWorker

{

    void ExecuteAsync();

}

​

public class WorkerA : IWorker

{

    public void ExecuteAsync()

    {

        Console.WriteLine("WorkerA");

    }

}

​

public class WorkerB : IWorker

{

    public void ExecuteAsync()

    {

        Console.WriteLine("WorkerB");

    }

}

​

public class MockWorker<T> : IWorker 

    where T : IWorker

{

    T m_worker;

    public MockWorker(T worker)

    {

        m_worker = worker;

    }

​

    public void ExecuteAsync()

    {

        m_worker.ExecuteAsync();

    }

}

​

public class Program

{

    public static void ExampleMethodThatTakesAWorker(IWorker worker)

    {

        worker.ExecuteAsync();

    }

​

    public static void Main()

    {

        var a = new WorkerA();

        ExampleMethodThatTakesAWorker(a);

        var b = new WorkerB();

        ExampleMethodThatTakesAWorker(b);

        var mockA = new MockWorker<WorkerA>(new WorkerA());

        ExampleMethodThatTakesAWorker(mockA);

        var mockB = new MockWorker<WorkerB>(new WorkerB());

        ExampleMethodThatTakesAWorker(mockB);

    }

}