override fun <T> mapCarsToFavorites(
        carsList: List<T>,
        findOp: (T, HotDealsResponse) -> Boolean,
        mapOp: (T, HotDealsResponse?) -> T
    ): Flowable<List<T>> =
        database.favoritesDao().getAllFavorites.map { favorites ->
            carsList.map { car ->
                val matchingCar = favorites.find { favorite -> findOp(car, favorite) }

                if (matchingCar != null) {
                    mapOp(car, matchingCar)
                }
            }

            carsList
        }