Running asynchronous code in Xcode Playground

async.swift

import Foundation
import XCPlayground
// Updated for Swift 2.0
let url:NSURL!=NSURL(string: "http://objectgraph.com")
NSURLSession.sharedSession().dataTaskWithURL(url) { data, response, error in
    print(NSString(data: data!, encoding: NSUTF8StringEncoding))
    print(error)
    print(response)
    }.resume()
print("This line is printed first as the network call is not complete")

//This will make sure your playground runs indefinitely

XCPlaygroundPage.currentPage.needsIndefiniteExecution = true