How to add / use default icons to navigation bar

Question

I want to use some of default iOS icons i.e.

in navigation bar.
Basically I don't know how to call image of that item (directly from native library - I know how to download it and place as custom image:)):

   var myButton:UIButton = UIButton.buttonWithType(UIButtonType.Custom) as! UIButton
   myButton.addTarget(self, action: "reload", forControlEvents: UIControlEvents.TouchUpInside)
   myButton.setImage(???, forState: <#UIControlState#>)

Answer 1

You can use UIBarButtonSystemItem this way:

let button = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Refresh, target: self, action: "someAction")
navigationItem.leftBarButtonItem = button

Result for leftBarButtonItem:

If you want to set it at right side you can use this code:

navigationItem.rightBarButtonItem = button

Result for rightBarButtonItem: