 // MARK: Types
 
 private enum CoderKey: String {
-    case Fullname
-    case Username
-    case UserID
+    case fullname
+    case username
+    case userID
 }
 
 // MARK: - FlickrUser: NSObject, NSCoding

    // MARK: NSCoding
    
    required convenience init?(coder aDecoder: NSCoder) {
        guard let fullname = aDecoder.decodeObject(forKey: CoderKey.Fullname.rawValue) as? String,
            let username = aDecoder.decodeObject(forKey: CoderKey.Username.rawValue) as? String,
            let userID = aDecoder.decodeObject(forKey: CoderKey.UserID.rawValue) as? String else {
                return nil
        }
        

    }
    
    func encode(with aCoder: NSCoder) {
        aCoder.encode(fullname, forKey: CoderKey.fullname.rawValue)
        aCoder.encode(username, forKey: CoderKey.username.rawValue)
        aCoder.encode(userID, forKey: CoderKey.userID.rawValue)
    }
    
}
