gistfile1.swift

class HttpClient {
    typealias completeClosure = ( _ data: Data?, _ error: Error?)->Void
    func get( url: URL, callback: @escaping completeClosure ) {
        let request = NSMutableURLRequest(url: url)
        request.httpMethod = "GET"
        let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
            callback(data, error)
        }
        task.resume()
    }
}