public class Sequence<TSubject> : CompositeBehavior<TSubject>
    {
        public override BehaviorStatus Update(TSubject subject, IBehaviorState state, TimeSpan ellapsedTime)
        {
            var status = CurrentBehavior.Update(subject, state, ellapsedTime);
            if (status == BehaviorStatus.Success)
            {
                _currentChildIndex++;
                if (_currentChildIndex >= Children.Count)
                {
                    return BehaviorStatus.Success;
                }
                CurrentBehavior.OnEnter(subject, state);
            }
            else if (status == BehaviorStatus.Failure)
            {
                return BehaviorStatus.Failure;
            }
            return BehaviorStatus.Running;
        }

        public override void OnEnter(TSubject subject, IBehaviorState state)
        {
            base.OnEnter(subject, state);
            _currentChildIndex = 0;
        }

        private int _currentChildIndex;

        protected Behavior<TSubject> CurrentBehavior => Children[_currentChildIndex];
    }