BEMCheckBox "extension" to support some content view to be highlighted when the checkbox is checked

BEMCheckBoxWithView.swift

import UIKit
import BEMCheckBox

//BEMCheckBox does not have any text or image next to the checkbox itself
//This class helps a bit with that

@IBDesignable

class BEMCheckBoxWithView: BEMCheckBox {
//this is the view that stands near checkbox
//set tint color, it will be used when checkbox is selected
    @IBOutlet weak var contentView: UIView!
    
    //for this to work you need to add 
    //- (void)_setOn:(BOOL)on animated:(BOOL)animated notifyGroup:(BOOL)notifyGroup
    //in BEMCheckBox.h class description (to make it public)
    override func _set(on: Bool, animated: Bool, notifyGroup: Bool) {
        super._set(on: on, animated: animated, notifyGroup: notifyGroup)
        
        //set tint to the content view, whatever it is
        if contentView is UIImageView {
            let contentView = self.contentView as! UIImageView
            contentView.image = contentView.image?.withRenderingMode(on ? .alwaysTemplate : .alwaysOriginal)
            contentView.tintColorDidChange()
        }
    }
}