Variable in extension has default value

UIViewController+InspectableAttribute.swift

struct InspectableComponent {
    var isHideBackBarButtonTitle = true
}

protocol HasInspectableComponent {
    var inspectableComponent: InspectableComponent { get set }
}

protocol InspectableAttribute: HasInspectableComponent { }

extension InspectableAttribute {
    var isHideBackBarButtonTitle: Bool {
        get { return inspectableComponent.isHideBackBarButtonTitle }
        set { inspectableComponent.isHideBackBarButtonTitle = newValue }
    }
}

extension UIViewController: InspectableAttribute {
    private struct AssociatedKey {
        static var inspectableComponent = "UIViewController.inspectableComponent"
    }
    
    var inspectableComponent: InspectableComponent {
        get {
            guard let component = objc_getAssociatedObject(self, &AssociatedKey.inspectableComponent) as? InspectableComponent else {
                return InspectableComponent()
            }
            return component
        }
        set {
            objc_setAssociatedObject(self, &AssociatedKey.inspectableComponent, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }
}