'Get all content ratings for this app in REGION for CATEGORY.
(e.g. give me the content ratings for a game listed in a Brazil.)'

def content_ratings_in(self, region, category=None):

    if (category and (not self.listed_in(region, category))):
        return []
    rb = []
    if (not region.ratingsbody):
        rb = mkt.ratingsbodies.GENERIC.id
    else:
        rb = region.ratingsbody.id
    return list(self.content_ratings.filter(ratings_body=rb).order_by('rating'))
