在FSCalendar中使用RxSwift的DelegateProxy时出错

import RxSwift
import RxCocoa
import FSCalendar

class FSCalendarDelegateProxy: DelegateProxy<FSCalendar, FSCalendarDelegate>, DelegateProxyType, FSCalendarDelegate {

    weak private(set) var calendar: FSCalendar?

    init(calendar: FSCalendar) {
        self.calendar = calendar
        super.init(parentObject: calendar, delegateProxy: FSCalendarDelegateProxy.self)
    }

    static func registerKnownImplementations() {
        self.register { FSCalendarDelegateProxy(calendar: $0) }
    }

    static func currentDelegate(for object: FSCalendar) -> FSCalendarDelegate? {
        return object.delegate
    }

    static func setCurrentDelegate(_ delegate: FSCalendarDelegate?, to object: FSCalendar) {
        object.delegate = delegate
    }
}

extension Reactive where Base: FSCalendar {

    var delegate: DelegateProxy<FSCalendar, FSCalendarDelegate> {
        return FSCalendarDelegateProxy.proxy(for: base)
    }

    var didSelectDate: ControlEvent<Date> {
        let source = delegate.methodInvoked(#selector(FSCalendarDelegate.calendar(_:didSelect:at:)))
            .map { parameters in
                return parameters[1] as! Date
            }
        return ControlEvent(events: source)
    }

    // 添加其他代理方法的转化
    // ...

}

let calendar = FSCalendar()
// 设置代理
calendar.rx.setDelegate(delegate).disposed(by: disposeBag)

// 监听日期选择事件
calendar.rx.didSelectDate
    .subscribe(onNext: { date in
        // 处理日期选择事件
    })
    .disposed(by: disposeBag)