Calling a ViewController from Storyboard Programmatically in iOS Xcode Swift 4.2

Mac 10.14.5
Xcode 10.2.1
Swift 4.2

How to call a ViewController from Storyboard programmatically
This sample targets Main.storyboard. Make sure to clear the settings beforehand:
“General” > “Deployment Info” > “Main Interface”

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
 
    var window: UIWindow?   //Main Window
 
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
 
        window = UIWindow(frame: UIScreen.main.bounds)
        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let viewController = storyboard.instantiateInitialViewController()
        window?.rootViewController = viewController
        window?.makeKeyAndVisible()
 
        return true
    }
}