private OperationResponse ItemOperationGetProperties(Item item, GetProperties operation)
        {
            if (item.Disposed)
            {
                return operation.GetOperationResponse((int)ReturnCode.ItemNotFound, "ItemNotFound");
            }

            if (item.Properties != null)
            {
                if (operation.PropertiesRevision.HasValue == false || operation.PropertiesRevision.Value != item.PropertiesRevision)
                {
                    var properties = new ItemProperties
                        {
                            ItemId = item.Id,
                            PropertiesRevision = item.PropertiesRevision,
                            PropertiesSet = new Hashtable(item.Properties)
                        };

                    var eventData = new EventData((byte)EventCode.ItemProperties, properties);
                    this.Peer.SendEvent(eventData, new SendParameters { ChannelId = Settings.ItemEventChannel });
                }
            }

            // no response sent
            operation.OnComplete();
            return null;
        }
        /// <summary>
        /// Handles operation GetProperties: Sends event ItemProperties to the client.
        /// </summary>
        public OperationResponse OperationGetProperties(PeerBase peer, OperationRequest request, SendParameters sendParameters)
        {
            var operation = new GetProperties(peer.Protocol, request);
            if (!operation.IsValid)
            {
                return new OperationResponse(request.OperationCode) { ReturnCode = (int)ReturnCode.InvalidOperationParameter, DebugMessage = operation.GetErrorMessage() };
            }

            operation.OnStart();
            Item item;
            bool actorItem = this.TryGetItem(operation.ItemId, out item);
            if (actorItem == false)
            {
                if (this.World.ItemCache.TryGetItem(operation.ItemId, out item) == false)
                {
                    return operation.GetOperationResponse((int)ReturnCode.ItemNotFound, "ItemNotFound");
                }
            }

            if (actorItem)
            {
                // we are already in the item thread, invoke directly
                return this.ItemOperationGetProperties(item, operation);
            }
            else
            {
                // second parameter (peer) allows us to send an error event to the client (in case of an error)
                item.Fiber.Enqueue(() => this.ExecItemOperation(() => this.ItemOperationGetProperties(item, operation), sendParameters));

                // operation is continued later
                return null;
            }
        }