How to use view controller containment

https://www.hackingwithswift.com/example-code/uikit/how-to-use-view-controller-containment

private func add(asChildViewcontroller viewController: UIViewController){

// Add Child View Controller

addChild(viewController)

// Add Child View as Subview

view.addSubview(viewController.view)

// Configure Child View

viewController.view.frame = view.bounds

viewController.view.autoresizingMask = [.flexibleWidth,.flexibleHeight]

// Notify Child View Controller

viewController.didMove(toParent: self)

}

private func move(asChildViewcontroller viewController: UIViewController){

// Notify Child View Controller

viewController.willMove(toParent: self)

// Remove Child View From Superview

viewController.view.removeFromSuperview()

// Notify Child View Controller

viewController.didMove(toParent: self)

}