     super.viewWillLayoutSubviews()
     layoutBottomNavBar()
   }
-
-  #if swift(>=3.2)
-  @available(iOS 11, *)
-  override func viewSafeAreaInsetsDidChange() {
-    super.viewSafeAreaInsetsDidChange()
-    layoutBottomNavBar()
-  }
-  #endif
 
   override func viewWillAppear(_ animated: Bool) {
     super.viewWillAppear(animated)


  init() {
    super.init(nibName: nil, bundle: nil)
  }

  @available(*, unavailable)

  
  func layoutBottomNavBar() {
    let size = bottomNavBar.sizeThatFits(view.bounds.size)
    var bottomNavBarFrame = CGRect(x: 0,
                                   y: view.bounds.height - size.height,
                                   width: size.width,
                                   height: size.height)
    if #available(iOS 11.0, *) {
      bottomNavBarFrame.size.height += view.safeAreaInsets.bottom
      bottomNavBarFrame.origin.y -= view.safeAreaInsets.bottom
    }
    bottomNavBar.frame = bottomNavBarFrame
  }

