public async Task RegisterOrUpdateReminderAsync(string reminderName, TimeSpan dueTime)
 {
     if (Controller.TrackingEnabled)
     {
         Controller.Track(new WorkflowInstanceReminderRecord(Id, WorkflowDefinition.DisplayName,
                                                             Tracking.WorkflowInstanceStates.ReminderRegistered, reminderName, DefinitionIdentity));
         await IfHasPendingThenFlushTrackingRecordsAsync();
     }
     await host.RegisterOrUpdateReminderAsync(reminderName, dueTime);
 }