swift: request a web page.
//: Playground - noun: a place where people can play
import Foundation
import PlaygroundSupport
URLCache.shared = URLCache(memoryCapacity: 0, diskCapacity: 0, diskPath: nil)
let url = URL(string: "http://www.baidu.com")
let task = URLSession.shared.dataTask(with: url!) {data, response, error in
guard let data = data, error == nil else { return }
print(NSString(data: data, encoding: String.Encoding.utf8.rawValue))
}
#if ABC
print("hahahahah")
#endif
print("begin")
task.resume()
PlaygroundPage.current.needsIndefiniteExecution = true