public override async Task VerifyStandaloneXml(
            StandaloneVerificationRequest request,
            IServerStreamWriter <StandaloneVerificationResponse> responseStream,
            ServerCallContext context)
        {
            try
            {
                _msg.InfoFormat("Starting stand-alone verification request from {0}",
                                context.Peer);
                _msg.DebugFormat("Request details: {0}", request);

                Action <LoggingEvent> action =
                    SendInfoLogAction(responseStream, ServiceCallStatus.Running);

                using (MessagingUtils.TemporaryRootAppender(new ActionAppender(action)))
                {
                    Func <ITrackCancel, ServiceCallStatus> func =
                        trackCancel => VerifyStandaloneXmlCore(request, responseStream,
                                                               trackCancel);

                    ServiceCallStatus result =
                        await GrpcServerUtils.ExecuteServiceCall(
                            func, context, _singleStaThreadScheduler);

                    _msg.InfoFormat("Verification {0}", result);
                }
            }
            catch (Exception e)
            {
                _msg.Error($"Error verifying quality for request {request}", e);

                SendFatalException(e, responseStream);
                SetUnhealthy();
            }
        }