Method does not override in Superclass Swift 3

Question

I am convert my code in swift 3 They give me error method does not override in superclass.

override func prefersStatusBarHidden() -> Bool {

    var statusBarHidden: Bool

    switch statusBarStyle {
    case .hidden:
        statusBarHidden = true
    default:
        statusBarHidden = false
    }

    if visible || contentViewContainer.frame.origin.y <= 0, let cntViewController = contentViewController {
        statusBarHidden = cntViewController.prefersStatusBarHidden
    }

    return statusBarHidden
}