Gold Challenge - tough one

iOS Programming (7th Edition) 9. UITableView and UITableViewController
5

I’m still struggling to implement this.

For one (and please don’t give me your code), I don’t have a proper implementation for getSectionItems:

func getSectionItems(for section: Int) -> [Item] {
    if section == 0 {
        return itemStore.over50Items
    } else {
        return itemStore.under50Items
    }
    // I figure there's more to it than this
}

More broadly, why do the authors expect readers to take these huge leaps (solving Gold Challenges) when (most) readers can barely walk?

What am I missing? I read each chapter, I try to understand Apple Documentation as best I can. Yet I still feel wholly ill-equipped. And therefore stuck. Do I need to stop this book and pour through Apple’s Swift book, or return to more “remedial” how-to-program materials?

(I commented on my frustrations a bit more here: [How to read Apple Developer Documentation])