Swift - Extend UIButton to save an object

extend-uibutton-save-object.swift

private var associationKey: UInt8 = 0

extension UIButton {
    
    var objectRef: String! {
        get {
            return objc_getAssociatedObject(self, &associationKey) as? String
        }
        set(newValue) {
            objc_setAssociatedObject(self, &associationKey, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN)
        }
    }
}

//How to use it
var btnObj = UIButton()
btnObj.objectRef = object // This can be a viewcontroller, navigationcontroller etc