NSImageView with Fill Aspect Ratio for Swift 4/5+

NSImageViewFill.swift

//
//  NSImageViewFill.swift
//  NSImageView with Fill Aspect Ratio
//  Swift 4.0+
//
//  Written by (source) https://stackoverflow.com/a/46262418/200041
//  I take no credit in this but it's too awesome not to gist.
//

import Cocoa

open class NSImageViewFill : NSImageView {
        
        open override var image: NSImage? {
            set {
                self.layer = CALayer()
                self.layer?.contentsGravity = CALayerContentsGravity.resizeAspectFill
                self.layer?.contents = newValue
                self.wantsLayer = true
                
                super.image = newValue
            }
            
            get {
                return super.image
            }
        }
}