Am having trouble moving code into a separate function

From within my GameViewController's viewDidLoad() function I do two things:

1- I create a sub UIVIew, myView, which is added to the main view,

2- I call my function, addConstraints, which is in the GameViewController's code.

When I create GameScene, self.myView.frame.width & self.myView.frame.height contain the correct values, and abide by the safeAreaLayout guides.

I want to make my code clearer, so I've moved the addConstraints function to a separate file. But when I run my app that way self.myView.frame.width & self.myView.frame.height are zero.

So am curious if I am somehow translating the function incorrectly, or maybe this is something I can't move outside of the main code?

The first block is the original code, the 2nd is the function

Code Block 
//located with GameViewControl		
private func addConstraints(){
				var constraints = [NSLayoutConstraint]()
				
				constraints.append(myView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor))
				constraints.append(myView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor))
				constraints.append(myView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor))
				constraints.append(myView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor))
				NSLayoutConstraint.activate(constraints)
		}

translated into a function

Code Block 
//called from GameViewControl
		createConstraints(view: myView)
		....
				
//located outside of GameViewControl
func createConstraints(view: UIView) {
		var constraints = [NSLayoutConstraint]()
										
		constraints.append(view.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor))
		constraints.append(view.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor))
		constraints.append(view.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor))
		constraints.append(view.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor))
										
		NSLayoutConstraint.activate(constraints)
}

And here is the full file of GameViewControl

Code Block 
import UIKit
import SpriteKit
class GameViewController: UIViewController {
		
		private let myView : UIView = {
				let myView = UIView()
				setViewAttributes(view: myView)
				return myView
		}()
		private func addConstraints(){
				 var constraints = [NSLayoutConstraint]()
				//add
				 constraints.append(myView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor))
				 constraints.append(myView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor))
				 constraints.append(myView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor))
				 constraints.append(myView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor))
				
				//activate
				 NSLayoutConstraint.activate(constraints)
		 }
		
		override func viewDidLoad() {
				super.viewDidLoad()
				#if DEBUG
						print ("viewDidLoad")
				#endif
				
				if let view = self.view as! SKView? {
						getScreenDimensions (screen: &screenDims)
						view.addSubview(myView)
						addConstraints()
						var scene : GameScene!
						DispatchQueue.main.async { scene = GameScene(size: CGSize(width: self.myView.frame.width, height: self.myView.frame.width))
								scene.anchorPoint = CGPoint(x: 0.0, y: 0.0)
								scene.backgroundColor = .clear
								scene.scaleMode = .aspectFit
								view.isHidden = false
								view.presentScene(scene)
						}
						view.ignoresSiblingOrder		= true
						view.showsFPS							 = true
						view.showsNodeCount				 = true
						view.showsPhysics					 = true
				}
		}
		
		override func viewDidLayoutSubviews() {
				super.viewDidLayoutSubviews()
				#if DEBUG
						print ("GVC viewDidLayoutSubviews")
				#endif
				myGlobalVars.sceneRect = view.frame
				
				if #available(iOS 11.0, *) {
						myGlobalVars.topSafeArea		= view.safeAreaInsets.top
						myGlobalVars.bottomSafeArea = view.safeAreaInsets.bottom
				} else {
						myGlobalVars.topSafeArea		= topLayoutGuide.length
						myGlobalVars.bottomSafeArea = bottomLayoutGuide.length
				}
		}
		
		override var shouldAutorotate: Bool {
				#if DEBUG
						print ("shouldAutorotate")
				#endif
				return false
		}
		override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
				#if DEBUG
						print ("supportedInterfaceOrientations")
				#endif
				if UIDevice.current.userInterfaceIdiom == .phone {
						return .allButUpsideDown
				} else {
						return .all
				}
		}
		override var prefersStatusBarHidden: Bool {
				#if DEBUG
						print ("prefersStatusBarHidden")
				#endif
				return false
		}
}

The call to function setViewAttributes does pass the view to a function, and I have verified that that function is working.

Code Block 
func setViewAttributes(view: UIView)
{
		view.alpha								= 0.0
		view.frame.size.height		= UIScreen.main.nativeBounds.height
		view.frame.size.width		 = UIScreen.main.nativeBounds.width
		view.translatesAutoresizingMaskIntoConstraints = false
		view.backgroundColor			= .clear
}

Code Block 
override func viewWillLayoutSubviews() {
		super.viewWillLayoutSubviews()
		#if DEBUG
				print ("GVC viewWillLayoutSubviews")
		#endif
		let safeAreaInsets = self.view.safeAreaInsets;
}