Example of broken DelegateProxy (rxSwift 4.0) for pure Swift delegate protocols

RxJTAppleCalendarDelegateProxy.swift

//
//  RxJTAppleCalendarDelegateProxy.swift
//  bookingclient
//
//  Created by Mats on 7/9/17.
//  Copyright © 2017 Ramwise. All rights reserved.
//

import JTAppleCalendar
import RxSwift
import RxCocoa

extension JTAppleCalendarView: HasDelegate {
	public typealias Delegate = JTAppleCalendarViewDelegate
}

internal class RxJTAppleCalendarDelegateProxy
	: DelegateProxy<JTAppleCalendarView, JTAppleCalendarViewDelegate>
	, DelegateProxyType
	, JTAppleCalendarViewDelegate {
	
	internal init(parentObject: JTAppleCalendarView) {
		super.init(parentObject: parentObject, delegateProxy: RxJTAppleCalendarDelegateProxy.self)
	}
	
	internal static func registerKnownImplementations() {
		self.register { RxJTAppleCalendarDelegateProxy(parentObject: $0) }
	}
	
	lazy var didSelectPublishSubject = PublishSubject<(date: Date, cell: JTAppleCell?, cellState: CellState)>()
	lazy var didDeselectPublishSubject = PublishSubject<(date: Date, cell: JTAppleCell?, cellState: CellState)>()
  
	internal func calendar(_ calendar: JTAppleCalendarView, didSelectDate date: Date, cell: JTAppleCell?, cellState: CellState) {
		didSelectPublishSubject.on(.next((date: date, cell: cell, cellState: cellState)))
		
		(self.forwardToDelegate() as? JTAppleCalendarViewDelegate)?.calendar(calendar, didSelectDate: date, cell: cell, cellState: cellState)
	}
	
	internal func calendar(_ calendar: JTAppleCalendarView, didDeselectDate date: Date, cell: JTAppleCell?, cellState: CellState) {
		didDeselectPublishSubject.on(.next((date: date, cell: cell, cellState: cellState)))
    
		(self.forwardToDelegate() as? JTAppleCalendarViewDelegate)?.calendar(calendar, didDeselectDate: date, cell: cell, cellState: cellState)
	}
	
	deinit {
		didSelectPublishSubject.on(.completed)
		didDeselectPublishSubject.on(.completed)
	}
}