import SwiftyCoreData

class ViewModel {

    // Create SCDController with given ObjectType and ManagedObjectType and NSPersistentContainer
    let dbController = SCDController<Object, ManagedObject>(with: persistanceContainer)

    func loadCache() {
        dbController.fetchAll {
            // Do stuff with your fetched objects (Cats)
        }
    }
}

import CoreData
import SwiftyCoreData

@objc(CatManagedObject)
public class CatManagedObject: NSManagedObject {

    @NSManaged public var name: String?
    @NSManaged public var weight: Double
    @NSManaged public var age: Int16

    @nonobjc public class func fetchRequest() -> NSFetchRequest<CatEntity> {
        return NSFetchRequest<CatManagedObject>(entityName: "CatManagedObject")
    }
}

/* Conform to SCDObjectConvertible */
extension CatManagedObject: SCDObjectConvertible {

    // Associate type of Object we will be converting to
    public typealias Object = Cat

    // Implement mapping algortihm between our ManagedObject and Object
    public func toObject() -> Cat? {
        guard let name = name else { return nil }

        return Cat(name: name, weight: weight, age: Int(age), managedObjectID: objectID)
    }
}

import CoreData
import SwiftyCoreData

// Note: Our model has to be public since SwiftyCoreData need information about it
public struct Cat {

    let name: String
    let weight: Double
    let age: Int

    // Note: It's good idea to store NSManagedObjectID for later purpose
    var managedObjectID: NSManagedObjectID?
}

/* Conform to SCDManagedObjectConvertible */
extension Cat: SCDManagedObjectConvertible {

    // Here implement algorith for putting our object in data base context
    // We need it for saving etc.
    public func put(in context: NSManagedObjectContext) {
        let catEntity = CatEntity(context: context)
        catEntity.name = self.name
        catEntity.weight = weight
        catEntity.age = Int16(age)
    }
}