     }
     
     fileprivate func permanentCacheFileURL(key: String, variant: Int64) -> URL {
-        return self.permanentStorageDirectory.appendingPathComponent("\(key)::\(variant)", isDirectory: false)
+        return self.permanentStorageDirectory.appendingPathComponent("\(key)||\(variant)", isDirectory: false)
     }
     
     fileprivate func fetchCacheItem(key: String, variant: Int64, moc: NSManagedObjectContext) -> CacheItem? {

        guard let siteURL = (url as NSURL).wmf_site, let imageName = WMFParseImageNameFromSourceURL(url) else {
            return nil
        }
        return siteURL.absoluteString + "::" + imageName
    }
    
    fileprivate func variantForURL(_ url: URL) -> Int64 { // A return value of 0 indicates the original size

    }
    
    fileprivate func createCacheItem(key: String, variant: Int64, moc: NSManagedObjectContext) -> CacheItem? {
        guard let entity = NSEntityDescription.entity(forEntityName: "CacheItem", in: moc) else {
            return nil
        }
        let item = CacheItem(entity: entity, insertInto: moc)
        item.key = key
        item.variant = variant
        item.date = NSDate()
