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)
}