let indicator = NVActivityIndicatorView(frame: CGRect(x: 160, y: 300, width: 50, height: 50), type: .ballRotateChase, color: .black, padding: 0)
self.view.addSubview(indicator)

DispatchQueue.main.async {
    indicator.startAnimating()
    print("isAnimating : \(indicator.isAnimating)")
}

DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
    indicator.stopAnimating()
    print("isAnimating : \(indicator.isAnimating)")
}