public IObservable <ITransition> Start() =>
getOldestUnsynced()
.SingleAsync()
.Select(entity =>
entity != null
? (ITransition)ChangeFound.Transition(entity)
: NoMoreChanges.Transition());
public IObservable <ITransition> Start() =>
dataSource
.Get()
.Where(entity => entity.SyncStatus == SyncStatus.SyncNeeded)
.SingleOrDefaultAsync()
.Select(entity =>
entity != null
? (ITransition)ChangeFound.Transition(entity)
: NoMoreChanges.Transition());