/// <summary>
 /// Stops the given Subscriber from receiving any future log entries
 /// </summary>
 /// <param name="subscriber"></param>
 public void Unsubscribe(ScenarioLogSubscriber subscriber)
 {
     subscribers.Remove(subscriber);
 }
 /// <summary>
 /// Ensures the given Subscriber receives any future log entries
 /// </summary>
 /// <param name="subscriber"></param>
 public void Subscribe(ScenarioLogSubscriber subscriber)
 {
     subscribers.Add(subscriber);
 }