public static unsafe void Dispose(ref DeliveryHandle handle)
        {
            fixed(DeliveryHandle *h = &handle)
            {
                DeliveryHandleImp *himp = (DeliveryHandleImp *)h;

                DeliveryHandleImp.Dispose(Thread.CurrentProcess, *himp);
            }
        }
 public static extern void Dispose(DeliveryHandle handle);