.swift

DispatchQueue.global(qos: .background).async {
    let jsonDownloader: JsonDownloader = JsonDownloader()
    let imageDownloader: ImageDownloader = ImageDownloader()
    
    let json: [String: AnyObject] = jsonDownloader.downloadContentsOfUrl("ourUrl.com")
    
    let image: UIImage = imageDownloader.downloadImage(URL(string: json["image_url"]))
    
    DispatchQueue.main.async {
        // -- SNIP -- Add image to UIImageView and add a subview in UIView
    }
}