protected override void OnFileChanged(string fileKey, string filePath)
        {
            var subj = typeof(AppendOnlyDbChangeInfo).Name;
            var msg  = ComposeBroadcastMessage(fileKey, filePath);

            Task.Run(async() =>
            {
                //await MessageBroadcast.ToAllClients(subj, msg);
                await MBHub.BroadcastToAll(subj, msg);
            });
        }
        private async Task TestSend2()
        {
            try
            {
                //await MessageBroadcast.ToAllClients("subj here", "test MessageBroadcast.ToAllClients");
                await MBHub.BroadcastToAll("subj here", "test MessageBroadcast.ToAllClients");

                CommonLogs.Add("MessageBroadcast sent");
            }
            catch (Exception ex)
            {
                CommonLogs.Add(ex);
            }
        }