gistfile1.txt

extension URL {
  func fetch(completionHandler: ((Data) -> ())? = nil) {
    print("Request: \(self)")
    URLSession.shared.dataTask(with: self) {
      guard
        let response = $1 as? HTTPURLResponse, response.statusCode == 200,
        let data = $0, $2 == nil
        else { return }
      completionHandler?(data)
      }.resume()
  }
}


let url = URL()

url.fetch {

}