Singleton Swift class

MyClass.swift

final class MyClass {
    private init() {}
    private static var _shared: MyClass?
    public static var shared: MyClass {
        get {
            if _shared == nil {
                DispatchQueue.global().sync(flags: .barrier) {
                    if _shared == nil {
                        _shared = MyClass()
                    }
                }
            }
            return _shared!
        }
    }
    func someFuntion() {
    }
}