public void DeactivateOnIdle(ActivationId id)
        {
            ActivationData data;
            if (!Catalog.TryGetActivationData(id, out data)) return; // already gone

            data.ResetKeepAliveRequest(); // DeactivateOnIdle method would undo / override any current “keep alive” setting, making this grain immideately avaliable for deactivation.
            Catalog.DeactivateActivationOnIdle(data);
        }