public virtual void OnBeginContact(Actor otherActor, Box2DX.Collision.Shape shape, Box2DX.Collision.Shape otherShape)
        {
            bool canAdd = true;

            foreach (var actor in overlappingActors)
            {
                if (actor == otherActor)
                {
                    canAdd = false; break;
                }
            }
            if (canAdd)
            {
                overlappingActors.Add(otherActor);
            }
            owner.OnBeginContact(otherActor, shape, otherShape);
        }
 public virtual void OnEndContact(Actor otherActor, Box2DX.Collision.Shape shape, Box2DX.Collision.Shape otherShape)
 {
     overlappingActors.Remove(otherActor);
     owner.OnEndContact(otherActor, shape, otherShape);
 }