public void CompleteFlowNodeInstance(string id)
        {
            var evt = new FlowNodeInstanceCompletedEvent(Guid.NewGuid().ToString(), AggregateId, Version + 1, id, DateTime.UtcNow);

            Handle(evt);
            DomainEvents.Add(evt);
        }
        private void Handle(FlowNodeInstanceCompletedEvent evt)
        {
            var instance = GetInstance(evt.FlowNodeInstanceId);

            instance.State = FlowNodeStates.Complete;
            Version        = evt.Version;
            UpdateDateTime = evt.ExecutionDateTime;
        }