Using the following snippet as example, I know that `numRatings` implementation is necessary, but isn't the rest a little bit overkill? Do we really need to assign each field of the parent? <img width="489" alt="screen shot 2018-10-11 at 1 56 14 pm" src="https://user-images.githubusercontent.com/15667259/46786154-3b481600-cd5e-11e8-825a-5846e28a7b56.png">