问Swift - Predicate根据成员数组的属性过滤数组

EN

class MyClass2 : NSObject {
    var uid: Int = 0

    init(uid : Int) {
        self.uid = uid
    }
}

class MyClass3 : NSObject {
    var arr: [MyClass2]

    init(units: [MyClass2]) {
        arr = units
    }
}

var units1 = [MyClass2(uid: 1),MyClass2(uid: 2), MyClass2(uid: 3), MyClass2(uid: 4), MyClass2(uid: 5)]
var units2 = [MyClass2(uid: 4),MyClass2(uid: 5), MyClass2(uid: 6)]
var units3 = [MyClass2(uid: 3),MyClass2(uid: 5), MyClass2(uid: 7), MyClass2(uid: 1)]

var ids = [1,5]

var available3: [MyClass3] = [MyClass3(units: units1), MyClass3(units: units2), MyClass3(units: units3)]
var filtered3: [MyClass3] = []

let searchPredicate: NSPredicate = NSPredicate(format: " ANY arr.uid IN \(ids)") // needed predicate
print(searchPredicate.predicateFormat)
filtered3 = (available3 as NSArray).filteredArrayUsingPredicate(searchPredicate) as! [MyClass3]