giln

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?

    func application(_: UIApplication, didFinishLaunchingWithOptions _: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        window = UIWindow(frame: UIScreen.main.bounds)
        window?.backgroundColor = UIColor.white
        window?.makeKeyAndVisible()

giln

import UIKit

/// Extension used to facilitate adding child viewControllers in a viewController
public extension UIViewController {
    /// Embeds a view controller and also adds it's view in the view hierarchay
    ///
    /// - Parameter viewController: ViewController to add
    func add(asChildViewController viewController: UIViewController, anchored: Bool = true, subview: UIView? = nil) {
        let someView: UIView = subview ?? view