         }
     }
     
+    /**
+     Return image URL by desired size.
+     
+     - parameter imageSize: The desired image size, see ImageSize for options.
+     
+     - returns: Image URL string.
+     */
     func imageURLForSize(imageSize: ImageSize) -> String? {
         switch imageSize {
         case .Default:

        return fetchRequest
    }
    
    class func instancesForContentURLs(URLs: [String],
                                       managedObjectContext: NSManagedObjectContext) -> [Story]? {
        

        return results
    }
    
    /**
     Lookup Story instances by predicate.
     
     Looks up Story instances based on a supplied predicate.
     
     - parameter managedObjectContext: The managedObjectContext instance to execute a fetch against.
     - parameter predicate: The predicate to use in the fetch request.
     
     - returns: Array Story entities matching the predicate.
     */
    class func instancesInManagedObjectContext(managedObjectContext: NSManagedObjectContext,
                                               predicate: NSPredicate? = nil) -> [Story]? {
        
