 
 				for imageId in currentCache {
 					self.clearCache(for: imageId)
-					trace?.incrementCounter(named: "pruned")
+					self.refreshTrace?.incrementCounter(named: "pruned")
 					print("Pruned image \(imageId) from cache.")
 				}
 				progress.completedUnitCount += 1

						do {
							try self.store(value, for: image)
							observer.send(value: value)
							observer.sendCompleted()
						} catch let error as ImageServiceError {
							observer.send(error: error)
						} catch {}
					case let .failure(error):
						observer.send(error: ImageServiceError.FailedDownload(image: image,
																			  description: error.localizedDescription))
					}
				})
			} catch let error as ImageServiceError {

				var producers: [SignalProducer<UIImage, ImageServiceError>] = []
				for image in images {
					if !self.validateCache(for: image) {
						self.refreshTrace?.incrementCounter(named: "scheduled")
						producers.append(self.download(image: image))
					}
					if let index = currentCache.index(of: image.Id) {
