public PersistentSleeper(DateTime expires, CAwaitable awaitable, bool rootify)
            {
                _expires   = expires;
                _awaitable = awaitable;

                if (rootify)
                {
                    Roots.EntangleAnonymously(this);
                }
            }
            public CallAfterSleeper(DateTime expires, Action callAfterSleep, bool rootify)
            {
                _expires        = expires;
                _callAfterSleep = callAfterSleep;

                if (rootify)
                {
                    Roots.EntangleAnonymously(this);
                }
            }