public JobScheduler(ILogger logger,
                     IJobHistoryStore jobHistoryStore,
                     IJobStatusTrackerFactory jobStatusTrackerFactory,
                     IImportRunner importRunner,
                     IConfigValidator configValidator)
 {
     if (logger == null)
     {
         throw new ArgumentNullException(nameof(logger));
     }
     if (jobHistoryStore == null)
     {
         throw new ArgumentNullException(nameof(jobHistoryStore));
     }
     if (importRunner == null)
     {
         throw new ArgumentNullException(nameof(importRunner));
     }
     if (configValidator == null)
     {
         throw new ArgumentNullException(nameof(configValidator));
     }
     if (jobStatusTrackerFactory == null)
     {
         throw new ArgumentNullException(nameof(jobStatusTrackerFactory));
     }
     _logger                  = logger;
     _jobHistoryStore         = jobHistoryStore;
     _importRunner            = importRunner;
     _configValidator         = configValidator;
     _jobStatusTrackerFactory = jobStatusTrackerFactory;
 }