Cat.swift

import Foundation
import Realm
import RealmSwift

class Cat: Object, Decodable {
    @objc dynamic var catId: Int = 0
    @objc dynamic var name: String = ""
    @objc dynamic var breed: String = ""
    @objc dynamic var weight: Double = 0
        
    override static func primaryKey() -> String? {
        return "catId"
    }