override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "BookCell", for: indexPath) as! BookTableViewCell

        // Configure the cell...
        let book = books[indexPath.row]
        cell.nameLabel.text = book.object(forKey: "name") as? String
        cell.typeLabel.text = book.object(forKey: "genre") as? String
        cell.isbnLabel.text = book.object(forKey: "isbn") as? String

        // Set the default book image
        cell.thumbnailImageView.image = UIImage(named: "photo_album")

        // Check if the book image is stored in cache
        if let imageFileURL = imageCache.object(forKey: book.recordID) {
            // Fetch image from cache
            if let imageData = try? Data.init(contentsOf: imageFileURL as URL) {
                cell.thumbnailImageView.image = UIImage(data: imageData)
            }

        } else {
            // Fetch Image from Cloud in background
            let publicDatabase = CKContainer.default().publicCloudDatabase
            let fetchBookImageRecordsOperation = CKFetchRecordsOperation(recordIDs: [book.recordID])
            fetchBookImageRecordsOperation.desiredKeys = ["image"]
            fetchBookImageRecordsOperation.queuePriority = .veryHigh

            fetchBookImageRecordsOperation.perRecordCompletionBlock = { (record, recordID, error) -> Void in
                if let error = error {
                    print("Failed to get book image: \(error.localizedDescription)")
                    return
                }

                if let bookRecord = record {
                    OperationQueue.main.addOperation() {
                        if let image = bookRecord.object(forKey: "image") {
                            let bookImageAsset = image as! CKAsset

                            if let imageData = try? Data.init(contentsOf: bookImageAsset.fileURL) {
                                cell.thumbnailImageView.image = UIImage(data: imageData)
                            }

                            // Add the book image URL to cache
                            self.imageCache.setObject(bookImageAsset.fileURL as NSURL, forKey: book.recordID)
                        }
                    }
                }
            }

            publicDatabase.add(fetchBookImageRecordsOperation)
        }

        return cell
    }