Akka.Actor.ActorCell.Unwatch C# (CSharp) Method

        public IActorRef Unwatch(IActorRef subject)
        {
            var a = (IInternalActorRef)subject;
            if (!a.Equals(Self) && WatchingContains(a))
            {
                a.SendSystemMessage(new Unwatch(a, _self));
                MaintainAddressTerminatedSubscription(() =>
                {
                    _state = _state.RemoveWatching(a);
                }, a);
            }
            _state = _state.RemoveTerminated(a);
            return a;
        }