private async Task <ClientSessionChannel> CreateChannelAsync(string endpointUrl, CancellationToken token = default)
        {
            try
            {
                this.logger?.LogTrace($"Begin creating {nameof(ClientSessionChannel)} for {endpointUrl}");
                await this.CheckSuspension(token).ConfigureAwait(false);

                EndpointDescription endpoint;
                var mappedEndpoint = this.MappedEndpoints?.LastOrDefault(m => m.RequestedUrl == endpointUrl);
                if (mappedEndpoint?.Endpoint != null)
                {
                    endpoint = mappedEndpoint.Endpoint;
                }
                else
                {
                    endpoint = new EndpointDescription {
                        EndpointUrl = endpointUrl
                    };
                }

                var channel = new ClientSessionChannel(
                    this.LocalDescription,
                    this.CertificateStore,
                    this.UserIdentityProvider,
                    endpoint,
                    this.LoggerFactory,
                    this.Options);

                channel.Faulted += (s, e) =>
                {
                    this.logger?.LogTrace($"Error creating {nameof(ClientSessionChannel)} for {endpointUrl}. OnFaulted");
                    var ch = (ClientSessionChannel)s !;
                    try
                    {
                        ch.AbortAsync().Wait();
                    }
                    catch
                    {
                    }
                };

                channel.Closing += (s, e) =>
                {
                    this.logger?.LogTrace($"Removing {nameof(ClientSessionChannel)} for {endpointUrl} from channelMap.");
                    this.channelMap.TryRemove(endpointUrl, out _);
                };

                await channel.OpenAsync(token).ConfigureAwait(false);

                this.logger?.LogTrace($"Success creating {nameof(ClientSessionChannel)} for {endpointUrl}.");
                return(channel);
            }
            catch (Exception ex)
            {
                this.logger?.LogTrace($"Error creating {nameof(ClientSessionChannel)} for {endpointUrl}. {ex.Message}");
                throw;
            }
        }
        public async Task ConnnectToAllEndpoints()
        {
            // discover available endpoints of server.
            var getEndpointsRequest = new GetEndpointsRequest
            {
                EndpointUrl = EndpointUrl,
                ProfileUris = new[] { TransportProfileUris.UaTcpTransport }
            };

            logger.LogInformation($"Discovering endpoints of '{getEndpointsRequest.EndpointUrl}'.");
            var getEndpointsResponse = await DiscoveryService.GetEndpointsAsync(getEndpointsRequest);

            // for each endpoint and user identity type, try creating a session and reading a few nodes.
            foreach (var selectedEndpoint in getEndpointsResponse.Endpoints
                     .OrderBy(e => e.SecurityLevel))
            {
                foreach (var selectedTokenPolicy in selectedEndpoint.UserIdentityTokens)
                {
                    IUserIdentity selectedUserIdentity;
                    switch (selectedTokenPolicy.TokenType)
                    {
                    case UserTokenType.Certificate:
                        selectedUserIdentity = x509Identity;
                        break;

                    case UserTokenType.UserName:
                        selectedUserIdentity = new UserNameIdentity("root", "secret");
                        break;

                    case UserTokenType.Anonymous:
                        selectedUserIdentity = new AnonymousIdentity();
                        break;

                    default:
                        continue;
                    }

                    var channel = new ClientSessionChannel(
                        localDescription,
                        certificateStore,
                        selectedUserIdentity,
                        selectedEndpoint,
                        loggerFactory: loggerFactory);

                    await channel.OpenAsync();

                    logger.LogInformation($"Opened session with endpoint '{channel.RemoteEndpoint.EndpointUrl}'.");
                    logger.LogInformation($"SecurityPolicy: '{channel.RemoteEndpoint.SecurityPolicyUri}'.");
                    logger.LogInformation($"SecurityMode: '{channel.RemoteEndpoint.SecurityMode}'.");
                    logger.LogInformation($"UserIdentityToken: '{channel.UserIdentity}'.");

                    logger.LogInformation($"Closing session '{channel.SessionId}'.");
                    await channel.CloseAsync();
                }
            }
        }
        public async Task StructureTest()
        {
            var channel = new ClientSessionChannel(
                localDescription,
                certificateStore,
                new AnonymousIdentity(),
                EndpointUrl,
                loggerFactory: loggerFactory);

            await channel.OpenAsync();

            var readRequest = new ReadRequest
            {
                NodesToRead = new[]
                {
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Structure")
                    },
                },
            };

            var readResponse = await channel.ReadAsync(readRequest);

            foreach (var result in readResponse.Results)
            {
                StatusCode.IsGood(result.StatusCode)
                .Should().BeTrue();
            }

            // reading this node returns an array of ExtensionObjects
            var obj = readResponse.Results[0].Value;

            // create new DataValue for writing.  Most servers reject writing values with timestamps.
            var newValue = new DataValue(obj);

            var writeRequest = new WriteRequest
            {
                NodesToWrite = new[]
                {
                    new WriteValue {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Structure"), Value = newValue
                    },
                },
            };
            var writeResponse = await channel.WriteAsync(writeRequest);

            foreach (var result in writeResponse.Results)
            {
                StatusCode.IsGood(result)
                .Should().BeTrue();
            }

            logger.LogInformation($"Closing session '{channel.SessionId}'.");
            await channel.CloseAsync();
        }
        public async Task BrowseObjects()
        {
            var channel = new ClientSessionChannel(
                localDescription,
                certificateStore,
                new AnonymousIdentity(),
                EndpointUrl,
                SecurityPolicyUris.None,
                loggerFactory: loggerFactory);

            await channel.OpenAsync();

            var rds           = new List <ReferenceDescription>();
            var browseRequest = new BrowseRequest {
                NodesToBrowse = new[] { new BrowseDescription {
                                            NodeId = ExpandedNodeId.ToNodeId(ExpandedNodeId.Parse(ObjectIds.ObjectsFolder), channel.NamespaceUris), ReferenceTypeId = NodeId.Parse(ReferenceTypeIds.HierarchicalReferences), ResultMask = (uint)BrowseResultMask.TargetInfo, NodeClassMask = (uint)NodeClass.Unspecified, BrowseDirection = BrowseDirection.Forward, IncludeSubtypes = true
                                        } }, RequestedMaxReferencesPerNode = 1000
            };
            var browseResponse = await channel.BrowseAsync(browseRequest).ConfigureAwait(false);

            rds.AddRange(browseResponse.Results.Where(result => result.References != null).SelectMany(result => result.References));
            var continuationPoints = browseResponse.Results.Select(br => br.ContinuationPoint).Where(cp => cp != null).ToArray();

            while (continuationPoints.Length > 0)
            {
                var browseNextRequest = new BrowseNextRequest {
                    ContinuationPoints = continuationPoints, ReleaseContinuationPoints = false
                };
                var browseNextResponse = await channel.BrowseNextAsync(browseNextRequest);

                rds.AddRange(browseNextResponse.Results.Where(result => result.References != null).SelectMany(result => result.References));
                continuationPoints = browseNextResponse.Results.Select(br => br.ContinuationPoint).Where(cp => cp != null).ToArray();
            }

            rds
            .Should().NotBeEmpty();

            logger.LogInformation("+ Objects, 0:Objects, Object");
            foreach (var rd in rds)
            {
                logger.LogInformation("   + {0}, {1}, {2}", rd.DisplayName, rd.BrowseName, rd.NodeClass);
            }

            logger.LogInformation($"Closing session '{channel.SessionId}'.");
            await channel.CloseAsync();
        }
        public async Task CustomVectorAdd()
        {
            var channel = new ClientSessionChannel(
                localDescription,
                certificateStore,
                new AnonymousIdentity(),
                "opc.tcp://*****:*****@"  ------------------");
            logger.LogInformation($"  {result}");

            logger.LogInformation($"Closing session '{channel.SessionId}'.");
            await channel.CloseAsync();

            result.Z
            .Should().Be(6.0);
        }
        public async Task TransferSubscription()
        {
            var channel1 = new ClientSessionChannel(
                localDescription,
                certificateStore,
                new UserNameIdentity("root", "secret"),
                EndpointUrl,
                loggerFactory: loggerFactory);

            await channel1.OpenAsync();

            logger.LogInformation($"Opened session with endpoint '{channel1.RemoteEndpoint.EndpointUrl}'.");
            logger.LogInformation($"SecurityPolicy: '{channel1.RemoteEndpoint.SecurityPolicyUri}'.");
            logger.LogInformation($"SecurityMode: '{channel1.RemoteEndpoint.SecurityMode}'.");
            logger.LogInformation($"Activated session '{channel1.SessionId}'.");

            // create the keep alive subscription.
            var subscriptionRequest = new CreateSubscriptionRequest
            {
                RequestedPublishingInterval = 1000f,
                RequestedMaxKeepAliveCount  = 30,
                RequestedLifetimeCount      = 30 * 3,
                PublishingEnabled           = true,
            };
            var subscriptionResponse = await channel1.CreateSubscriptionAsync(subscriptionRequest).ConfigureAwait(false);

            var id = subscriptionResponse.SubscriptionId;

            void onPublish(PublishResponse pr)
            {
                // loop thru all the data change notifications and log them.
                var dcns = pr.NotificationMessage.NotificationData.OfType <DataChangeNotification>();

                foreach (var dcn in dcns)
                {
                    foreach (var min in dcn.MonitoredItems)
                    {
                        logger.LogInformation($"sub: {pr.SubscriptionId}; handle: {min.ClientHandle}; value: {min.Value}");
                    }
                }
            }

            void onPublishError(Exception ex)
            {
                logger.LogInformation("Exception in publish response handler: {0}", ex.GetBaseException().Message);
            }

            var token = channel1
                        .Where(pr => pr.SubscriptionId == id)
                        .Subscribe(onPublish, onPublishError);

            var itemsRequest = new CreateMonitoredItemsRequest
            {
                SubscriptionId = id,
                ItemsToCreate  = new MonitoredItemCreateRequest[]
                {
                    new MonitoredItemCreateRequest {
                        ItemToMonitor = new ReadValueId {
                            NodeId = NodeId.Parse("i=2258"), AttributeId = AttributeIds.Value
                        }, MonitoringMode = MonitoringMode.Reporting, RequestedParameters = new MonitoringParameters {
                            ClientHandle = 12345, SamplingInterval = -1, QueueSize = 0, DiscardOldest = true
                        }
                    }
                },
            };
            var itemsResponse = await channel1.CreateMonitoredItemsAsync(itemsRequest);

            await Task.Delay(3000);

            var channel2 = new ClientSessionChannel(
                localDescription,
                certificateStore,
                new UserNameIdentity("root", "secret"),
                EndpointUrl);

            await channel2.OpenAsync();

            var token2 = channel2
                         .Where(pr => pr.SubscriptionId == id)
                         .Subscribe(onPublish, onPublishError);

            var transferRequest = new TransferSubscriptionsRequest
            {
                SubscriptionIds   = new[] { id },
                SendInitialValues = true
            };
            var transferResult = await channel2.TransferSubscriptionsAsync(transferRequest);

            StatusCode.IsGood(transferResult.Results[0].StatusCode)
            .Should().BeTrue();
            logger.LogInformation($"Transfered subscriptions to new client.");

            await Task.Delay(3000);

            logger.LogInformation($"Closing session '{channel1.SessionId}'.");
            await channel1.CloseAsync();

            logger.LogInformation($"Closing session '{channel2.SessionId}'.");
            await channel2.CloseAsync();
        }
        public async Task StackTest()
        {
            var channel = new ClientSessionChannel(
                localDescription,
                certificateStore,
                new AnonymousIdentity(),
                EndpointUrl,
                loggerFactory: loggerFactory);

            await channel.OpenAsync();

            logger.LogInformation($"Opened session with endpoint '{channel.RemoteEndpoint.EndpointUrl}'.");
            logger.LogInformation($"SecurityPolicy: '{channel.RemoteEndpoint.SecurityPolicyUri}'.");
            logger.LogInformation($"SecurityMode: '{channel.RemoteEndpoint.SecurityMode}'.");
            logger.LogInformation($"Activated session '{channel.SessionId}'.");

            var readRequest = new ReadRequest
            {
                NodesToRead = new[]
                {
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.Boolean")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.SByte")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.Int16")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.Int32")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.Int64")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.Byte")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.UInt16")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.UInt32")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.UInt64")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.Float")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.Double")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.String")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.DateTime")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.Guid")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.ByteString")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.XmlElement")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.LocalizedText")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Scalar.QualifiedName")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Boolean")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.SByte")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Int16")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Int32")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Int64")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Byte")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.UInt16")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.UInt32")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.UInt64")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Float")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Double")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.String")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.DateTime")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.Guid")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.ByteString")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.XmlElement")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.LocalizedText")
                    },
                    new ReadValueId {
                        AttributeId = AttributeIds.Value, NodeId = NodeId.Parse("ns=2;s=Demo.Static.Arrays.QualifiedName")
                    },
                },
            };

            var sw = new Stopwatch();

            sw.Restart();
            for (int i = 0; i < 1; i++)
            {
                var readResponse = await channel.ReadAsync(readRequest);

                foreach (var result in readResponse.Results)
                {
                    StatusCode.IsGood(result.StatusCode)
                    .Should().BeTrue();
                    var obj = result.GetValue();
                }
            }

            sw.Stop();
            logger.LogInformation($"{sw.ElapsedMilliseconds} ms");

            logger.LogInformation($"Closing session '{channel.SessionId}'.");
            await channel.CloseAsync();
        }
        public async Task ReadHistorical()
        {
            var channel = new ClientSessionChannel(
                localDescription,
                certificateStore,
                new AnonymousIdentity(),
                "opc.tcp://localhost:48010",
                loggerFactory: loggerFactory);

            await channel.OpenAsync();

            logger.LogInformation($"Opened session with endpoint '{channel.RemoteEndpoint.EndpointUrl}'.");
            logger.LogInformation($"SecurityPolicy: '{channel.RemoteEndpoint.SecurityPolicyUri}'.");
            logger.LogInformation($"SecurityMode: '{channel.RemoteEndpoint.SecurityMode}'.");
            logger.LogInformation($"Activated session '{channel.SessionId}'.");

            var historyReadRequest = new HistoryReadRequest
            {
                HistoryReadDetails = new ReadRawModifiedDetails
                {
                    StartTime      = DateTime.UtcNow - TimeSpan.FromMinutes(10),
                    EndTime        = DateTime.UtcNow,
                    ReturnBounds   = true,
                    IsReadModified = false
                },
                NodesToRead = new[]
                {
                    new HistoryReadValueId
                    {
                        NodeId = NodeId.Parse("ns=2;s=Demo.History.DoubleWithHistory")
                    }
                },
            };
            var historyReadResponse = await channel.HistoryReadAsync(historyReadRequest);

            var result = historyReadResponse.Results[0];

            StatusCode.IsGood(result.StatusCode)
            .Should().BeTrue();
            logger.LogInformation($"HistoryRead response status code: {result.StatusCode}, HistoryData count: {((HistoryData)result.HistoryData).DataValues.Length}.");

#if false // UaCPPserver does not appear to store event history.
            {
                var historyReadRequest2 = new HistoryReadRequest
                {
                    HistoryReadDetails = new ReadEventDetails
                    {
                        StartTime = DateTime.UtcNow - TimeSpan.FromMinutes(10),
                        EndTime   = DateTime.UtcNow,
                        Filter    = new EventFilter // Use EventHelper to select all the fields of AlarmCondition.
                        {
                            SelectClauses = EventHelper.GetSelectClauses <AlarmCondition>()
                        }
                    },
                    NodesToRead = new[]
                    {
                        new HistoryReadValueId
                        {
                            NodeId = NodeId.Parse("ns=2;s=Demo.History.DoubleWithHistory")
                        }
                    },
                };
                var historyReadResponse2 = await channel.HistoryReadAsync(historyReadRequest2);

                var result2 = historyReadResponse2.Results[0];
                StatusCode.IsGood(result2.StatusCode)
                .Should().BeTrue();
                logger.LogInformation($"HistoryRead response status code: {result2.StatusCode}, HistoryEvent count: {((HistoryEvent)result2.HistoryData).Events.Length}.");

                // Use EventHelper to create AlarmConditions from the HistoryEventFieldList
                var alarms = ((HistoryEvent)result2.HistoryData).Events.Select(e => EventHelper.Deserialize <AlarmCondition>(e.EventFields));
            }
#endif

            logger.LogInformation($"Closing session '{channel.SessionId}'.");
            await channel.CloseAsync();
        }
        public async Task TestSubscription()
        {
            var channel = new ClientSessionChannel(
                localDescription,
                certificateStore,
                new AnonymousIdentity(),
                EndpointUrl,
                loggerFactory: loggerFactory);

            await channel.OpenAsync();

            logger.LogInformation($"Opened session with endpoint '{channel.RemoteEndpoint.EndpointUrl}'.");
            logger.LogInformation($"SecurityPolicy: '{channel.RemoteEndpoint.SecurityPolicyUri}'.");
            logger.LogInformation($"SecurityMode: '{channel.RemoteEndpoint.SecurityMode}'.");
            logger.LogInformation($"Activated session '{channel.SessionId}'.");

            var req = new CreateSubscriptionRequest
            {
                RequestedPublishingInterval = 1000.0,
                RequestedMaxKeepAliveCount  = 30,
                RequestedLifetimeCount      = 30 * 3,
                PublishingEnabled           = true,
            };
            var res = await channel.CreateSubscriptionAsync(req);

            var id = res.SubscriptionId;

            logger.LogInformation($"Created subscription '{id}'.");

            var req2 = new CreateMonitoredItemsRequest
            {
                SubscriptionId     = id,
                TimestampsToReturn = TimestampsToReturn.Both,
                ItemsToCreate      = new MonitoredItemCreateRequest[]
                {
                    new MonitoredItemCreateRequest
                    {
                        ItemToMonitor = new ReadValueId {
                            AttributeId = AttributeIds.Value, NodeId = NodeId.Parse(VariableIds.Server_ServerStatus_CurrentTime)
                        },
                        MonitoringMode      = MonitoringMode.Reporting,
                        RequestedParameters = new MonitoringParameters {
                            ClientHandle = 42, QueueSize = 2, DiscardOldest = true, SamplingInterval = 500.0
                        },
                    },
                },
            };
            var res2 = await channel.CreateMonitoredItemsAsync(req2);

            logger.LogInformation("Subscribe to PublishResponse stream.");
            var numOfResponses = 0;

            void onPublish(PublishResponse pr)
            {
                numOfResponses++;

                // loop thru all the data change notifications and log them.
                var dcns = pr.NotificationMessage.NotificationData.OfType <DataChangeNotification>();

                foreach (var dcn in dcns)
                {
                    foreach (var min in dcn.MonitoredItems)
                    {
                        logger.LogInformation($"sub: {pr.SubscriptionId}; handle: {min.ClientHandle}; value: {min.Value}");
                    }
                }
            }

            void onPublishError(Exception ex)
            {
                logger.LogInformation("Exception in publish response handler: {0}", ex.GetBaseException().Message);
            }

            var token = channel
                        .Where(pr => pr.SubscriptionId == id)
                        .Subscribe(onPublish, onPublishError);

            await Task.Delay(5000);

            logger.LogInformation($"Closing session '{channel.SessionId}'.");
            await channel.CloseAsync();

            numOfResponses
            .Should().BeGreaterThan(0);
        }