public Task StartAsync(CancellationToken cancellationToken)
 {
     _logger.LogInformation("Start task.");
     #if false
     IApplicationLifetime.ApplicationStarted sets _healthCheck.StartupTaskCompleted to true
     // Simulate the effect of a long-running startup task.
     Task.Run(async() =>
     {
         await Task.Delay(_delaySeconds * 1000);
         _healthCheck.StartupTaskCompleted = true;
         _logger.LogInformation($"Startup Background Service has started.");
     });
     #endif
     return(Task.CompletedTask);
 }