Download JSON with completion handler

import Cocoa

class LoadJSON: NSObject {

    func download() {
        let config = URLSessionConfiguration.default      // Session configuration
        let session = URLSession(configuration: config)  // load configuration into session
        let url = URL(string: "https://jsonplaceholder.typicode.com/users")
        let task = session.dataTask(with: url!, completionHandler: {
            (data, response, error) in
            if error != nil {
                print(error!.localizedDescription)
            } else {
                print(response!)
                print(data!)
            }  // end if error
        })  // end task
        task.resume()
    }  // end func}

}  // end class