Value of type 'UIView' has no member 'user'

gistfile1.txt

import UIKit

func bootstrap<T>(_ object: T?, with block: ((T?) -> T?)) -> T? {
    return block(object)
}

protocol Nibbable {
    
}

extension Nibbable {
    static var name: String {
        return String(describing: type(of: self)).components(separatedBy: ".")[0]
    }
    
    static var nib: UINib {
        return UINib(nibName: self.name, bundle: nil)
    }
}

extension Nibbable where Self: UIResponder {
    static func getRoot(withOwner owner: Any, options: [AnyHashable:Any]? = nil) -> Self? {
        return self.nib.instantiate(withOwner: owner, options: options).first as? Self
    }
}

class ContactDetailHeaderView: UIView, Nibbable {
    var user: String?
}

class ContactDetailTableViewController: UITableViewController {
    var user: String?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.tableView.backgroundView = bootstrap(ContactDetailHeaderView.getRoot(withOwner: self), with: { $0?.user = self.user })
    }
}