iOS RXSwift 4.2如何使用DelegateProxy实现cCentralManager的响应式扩展?

这是用于 CBCentralManager

extension CBCentralManager : HasDelegate {
    public typealias Delegate = CBCentralManagerDelegate
}

class RxCBCentralManagerDelegateProxy
  : DelegateProxy<CBCentralManager, CBCentralManagerDelegate>
  , DelegateProxyType
  , CBCentralManagerDelegate
{

   internal let stateBehaviorSubject: BehaviorSubject<CBManagerState>

   init(centralManager: CBCentralManager) {
       let subject = BehaviorSubject(value: centralManager.state)
       stateBehaviorSubject = subject

       super.init(parentObject: centralManager, delegateProxy: RxCBCentralManagerDelegateProxy.self)
   }

   func centralManagerDidUpdateState(_ central: CBCentralManager) {
       stateBehaviorSubject.onNext(central.state)
       _forwardToDelegate?.centralManagerDidUpdateState(central)
   }

   static func registerKnownImplementations() {
       self.register { RxCBCentralManagerDelegateProxy(centralManager: $0) }
   }

   deinit {
       stateBehaviorSubject.on(.completed)
   }
}

extension Reactive where Base : CBCentralManager {
   var delegate: DelegateProxy<CBCentralManager, CBCentralManagerDelegate> {
       return RxCBCentralManagerDelegateProxy.proxy(for: base)
   }

   var state: ControlEvent<CBManagerState> {
       let source = (delegate as! RxCBCentralManagerDelegateProxy)
          .stateBehaviorSubject
          .skip(1)
       return ControlEvent(events: source)
   }
}