Sample about get data from server, this case will be failed because not using @escaping

GetDataServerNonEscaping.swift

//: Playground - noun: a place where people can play
// nhathm01247@gmail.com

import Foundation
import UIKit
import PlaygroundSupport

PlaygroundPage.current.needsIndefiniteExecution = true

class ServerConnection: NSObject {
    let defaultSession = URLSession(configuration: URLSessionConfiguration.default)
    var dataTask: URLSessionDataTask?
    
    func getDataFromServer(url: String, completion: (String?) -> ()) {
        let url: URL = URL(string: url)!
        
        dataTask = defaultSession.dataTask(with: url) { data, response, error in
            if let error = error {
                print(error.localizedDescription)
                completion(nil)
            } else if let httpResponse = response as? HTTPURLResponse {
                if httpResponse.statusCode == 200 {
                    completion("Sucess get data from server")
                } else {
                    print("\(httpResponse.statusCode)")
                    completion(nil)
                }
            }
        }
        
        dataTask?.resume()
    }
}