Create easily a view in Playground to play with

SettingPlayground.swift

import UIKit
import PlaygroundSupport

let containerView = UIView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))

// Play with containerView
let targetView = UIView(frame: CGRect(x: containerView.bounds.midX, 
                                      y: containerView.bounds.midY, 
                                      width: 50.0, 
                                      height: 50.0))
containerView.addSubview(targetView)

PlaygroundPage.current.liveView = containerView