About Realm Swift SUBQUERY

class Child:Object{
    dynamic var status = false
    dynamic var name=""
    convenience init(name:String) {
        self.init()
        self.name = name
    }
}

class Parent:Object {
    let children=List<Child>()
    dynamic var name=""
    convenience init(name:String) {
        self.init()
        self.name = name
    }
}

classViewController:UIViewController {

    let realm=try!Realm()

    override func viewDidLoad(){
        super.viewDidLoad()
        setSampleData()
        procedure()
    }

    func procedure() {
        letpredicate=NSPredicate(format: "SUBQUERY(children,$c,$c.status==true).@count>0")
        print(realm.objects(Parent).filter(predicate).description)
    }

    funcsetSampleData(){
        try!realm.write{
            self.realm.deleteAll()
            let parent1 = Parent(name: "Parent1")
            let parent2 = Parent(name: "Parent2")
            let parent3 = Parent(name: "Parent3")
            letchild1 = Child(name: "Child1")
            letchild2 = Child(name: "Child2")
            letchild3 = Child(name: "Child3")
            letchild4 = Child(name: "Child4")
            letchild5 = Child(name: "Child5")
            self.realm.add (parent1)
            self.realm.add (parent2)
            self.realm.add (parent3)
            self.realm.add (child1)
            self.realm.add (child2)
            self.realm.add(child3)
            self.realm.add (child4)
            self.realm.add(child5)
            child1.status=false
            child2.status=true
            child3.status=false
            child4.status=true
            child5.status=false
            parent1.children.append(child1)
            parent1.children.append(child2)
            parent2.children.append(child3)
            parent2.children.append(child4)
            parent3.children.append(child5)
        }
    }

    override funcdidReceiveMemoryWarning(){
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}