Eu tento migrar delegado de DiffitivityViewDelegate para observável. Esta é a minha DificuldadeVistaDelegada:

@objc protocol DifficultyViewDelegate: class {
  func levelDidIncrease()
  func levelDidDecrease()
}

E minha dificuldadeView:

  weak var delegate: DifficultyViewDelegate?

  @IBAction func decreaseLevel(_ sender: Any) {
    delegate?.levelDidDecrease()
  }

  @IBAction func increaseLevel(_ sender: Any) {
    delegate?.levelDidIncrease()
  }

E este é o meu RxDiffitivityViewDelegateProxy

class RxDifficultyViewDelegateProxy: DelegateProxy, DelegateProxyType {
  static func currentDelegateFor(_ object: AnyObject) -> AnyObject? {
    let difficultyView: DifficultyView = object as! DifficultyView
    return difficultyView.delegate
  }

  static func setCurrentDelegate(_ delegate: AnyObject?, toObject object: AnyObject) {
    let difficultyView: DifficultyView = object as! DifficultyView
    difficultyView.delegate = delegate as? DifficultyViewDelegate
  }
}

Eu também adicionei uma extensão no meu DiffitivityView:

extension DifficultyView {
  public var rx_delegate: RxDifficultyViewDelegateProxy {
    return  RxDifficultyViewDelegateProxy.proxyForObject(RxDifficultyViewDelegateProxy.self)
  }

  public var rx_levelDidIncrease: Observable<Void> {
    return rx_delegate.methodInvoked(#selector(DifficultyViewDelegate.levelDidIncrease)).map { _ in return }
  }
}

Mas parece que quando eu faço:

difficultyView.rx_levelDidIncrease.asObservable().subscribe(onNext: {
  print("did increase")
}).addDisposableTo(disposeBag)

Nunca é chamado. Alguém tem alguma dica?