mapping RKTUser attributeFromDictionary id userID screen_name screenName name name RKTweet attributeFromDictionary id statusID text text url url in_reply_to_screen_name inReplyToScreenName favorited isFavorited relationship fromKeyPath user toKeyPath user classMapping RKTUser response statusCode 400 class RKErrorMessage class RKTweet request class RKTweet routes class RKTUserStatus route /status/user_timeline/:username class RKTweet route /trash