public WorkItemUpdateManager(ItemCollection <WorkItem> itemCollection, Predicate <WorkItem> filter, System.Action failedItemCountChanged)
 {
     _items  = itemCollection;
     _filter = filter;
     _failedItemCountChanged = failedItemCountChanged;
     _failures = new Dictionary <long, WorkItem>();
 }
 public StudyCountWatcher(System.Action onChanged)
 {
     _throttleTimer = new Timer(OnTimerElapsed, null, TimeSpan.FromSeconds(5));
     _onChanged     = onChanged;
 }