Как получить DivisionedFetchRequest с объектом связи в качестве идентификатора раздела

var body: some View {
        
    VStack(alignment: .leading) {
        ForEach(ranksFetcher.ranks, id: \.id) { rank in
            CardExpansionView(card: rank.card, num: rank.count, maxWidth: rank.width)
        }
    }
    .frame(maxWidth: .infinity, alignment: .leading)
    .onAppear() {
        if fetch {
            ranksFetcher.moc = moc
            ranksFetcher.maxWidth = viewWidth()
            ranksFetcher.fetch(yearmonth: yearmonth)
            fetch.toggle()
        }
    }
}

class RanksFetcher: NSObject, ObservableObject {
    var moc: NSManagedObjectContext?
    var maxWidth: CGFloat?
    
    @Published
    private(set) var ranks: [CardRankModel] = []
    
    func fetch(yearmonth: Int32) {
        let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "CardRecord")
        fetchRequest.predicate = NSPredicate(format: "month = %i", yearmonth)
        fetchRequest.propertiesToGroupBy = ["cardId"]
        fetchRequest.resultType = .dictionaryResultType
        
        // Defining column 'count'
        let expressDescription = NSExpressionDescription()
        expressDescription.resultType = .integer32
        let name = "count"
        expressDescription.name = name
        
        // Count witch column
        let cardId = NSExpression(forKeyPath: \CardRecord.cardId)
        let express = NSExpression(forFunction: "count:", arguments: [cardId])
        expressDescription.expression = express
        fetchRequest.propertiesToFetch = ["cardId", expressDescription]
        
        var groups = (try? moc!.fetch(fetchRequest) as? [[String: Any]]) ?? []
        groups.sort { e1, e2 in
            let i1 = e1["count"] as? Int32 ?? 0
            let i2 = e2["count"] as? Int32 ?? 0
            return i1 > i2
        }
        
        var cardIds = [String]()
        for gp in groups {
            cardIds.append(gp["cardId"] as! String)
        }
        
        let cardsFetchRequest = NSFetchRequest<Card>(entityName: "Card")
        cardsFetchRequest.predicate = NSPredicate(format: "cid in (%@)", cardIds)
        let cards = (try? moc!.fetch(cardsFetchRequest)) ?? []
        let cardMap = Dictionary.init(cards.map { ($0.cid, $0) }) { $1 }
        let maxWidth = maxWidth!
        let maxCount = groups.first?["count"] as? Int32
        
        var data: [CardRankModel] = []
        for gp in groups {
            let cardId = gp["cardId"] as! String
            let count = gp["count"] as? Int32 ?? 0
            if let card = cardMap[cardId] {
                let cardRankModel = CardRankModel(id: card.cid!, card: card, count: count, width: maxWidth * (CGFloat(count) / CGFloat(maxCount!)))
                data.append(cardRankModel)
            }
        }
        
        ranks = data
    }
}