An example of one of the samples...
...
override func viewDidLoad() {
super.viewDidLoad()
// Initialize your new subviews
let myBlueRectangle = UIView()
myBlueRectangle.layer.borderColor = view.tintColor.CGColor
myBlueRectangle.layer.borderWidth = 2
let myOrangeRectangle = UIView()
myOrangeRectangle.backgroundColor = SamplesColors.orange
// Add your subviews to the view heirarchy.
//
// * Notice here that myBlueRectangle is added as a subview of 'view', the view controller's view,
// while myOrangeRectangle is added as a subview of myBlueRectangle! Voilà! You have nested views!
// Now that each view is a subview of another view, we can use constraints to position them how we'd like!
//
view.addSubview(myBlueRectangle)
myBlueRectangle.addSubview(myOrangeRectangle)
...Enjoy!