/// <summary>
 /// Unsubscribe callback.
 /// </summary>
 /// <param name="eventAction">Event action.</param>
 /// <param name="keepEvent">GC optimization - clear only callback list and keep event for future use.</param>
 public void Unsubscribe <T> (EventBus.EventHandler <T> eventAction, bool keepEvent = false)
 {
     _eb.Unsubscribe(eventAction, keepEvent);
 }
 /// <summary>
 /// Subscribe callback to be raised on specific event.
 /// </summary>
 /// <param name="eventAction">Callback.</param>
 public void Subscribe <T> (EventBus.EventHandler <T> eventAction)
 {
     _eb.Subscribe(eventAction);
 }