what is a global state?
let space = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
let doneButton = UIBarButtonItem(title: buttonTitle, style: .done, target: self, action: #selector(doneButtonAction))
let cancelButton = UIBarButtonItem(title: cancelTitle, style: .plain, target: self, action: #selector(cancelButtonAction))
let barAccessory = UIToolbar(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: 44))
barAccessory.barStyle = .default
barAccessory.isTranslucent = true
barAccessory.barTintColor = .blue
barAccessory.setItems([cancelButton, space, doneButton], animated: false)
picker.addSubview(barAccessory)
self.view.bringSubviewToFront(picker)