Swift 3 - Download JPEG image and save to file - macOS - swift3

Question

I have a downloader class that downloads a file based on a given URL which then calls a completion passing it the contents of the file as NSData.
For the project that I'm using this in, the URL will be a JPEG image. The downloader works perfectly; I can use the result into NSImage and show it in a Image View Controller.
I would like to be able to save that NSData object to file.
After quite some time researching the internet on Google, StackOverflow, etc. and trying many suggestions, I cannot get the file to save.
Here is a playground of the Downloader class and my attempt to save the file:
//: Playground - noun: a place where people can play
import Cocoa
class NetworkService
{
lazy var configuration: URLSessionConfiguration = URLSessionConfiguration.default
lazy var session: URLSession = URLSession(configuration: self.configuration)
let url: NSURL
init(url: NSURL)
{
self.url = url
}
func downloadImage(completion: #escaping ((NSData) -> Void))
{
let request = NSURLRequest(url: self.url as URL)
let dataTask = session.dataTask(with: request as URLRequest) { (data, response, error) in
if error == nil {
if let httpResponse = response as? HTTPURLResponse {
switch (httpResponse.statusCode) {
case 200:
if let data = data {
completion(data as NSData)
}
default:
print(httpResponse.statusCode)
}
}
} else {
print("Error download data: \(error?.localizedDescription)")
}
}
dataTask.resume()
}
}
let IMAGE_URL = NSURL(string: "https://www.bing.com/az/hprichbg/rb/RossFountain_EN-AU11490955168_1920x1080.jpg")
let networkService = NetworkService(url: IMAGE_URL!)
networkService.downloadImage(completion: { (data) in
data.write(to: URL(string: "file://~/Pictures/image.jpg")!, atomically: false)
})
The playground console show nothing at all. Can anyone spot why its not working?
NOTE: The target is macOS, not iOS. Also, I'm a swift noob...
I did try this:
networkService.downloadImage(completion: { (imageData) in
let imageAsNSImage = NSImage(data: imageData as Data)
if let bits = imageAsNSImage?.representations.first as? NSBitmapImageRep {
let outputData = bits.representation(using: .JPEG, properties: [:])
do {
try outputData?.write(to: URL(string: "file://~/Pictures/myImage.jpg")!)
} catch {
print("ERROR!")
}
}
})

Answer 1

It could be a permission issue. You may try:
let picturesDirectory = FileManager.default.urls(for: .picturesDirectory, in: .userDomainMask)[0]
let imageUrl = picturesDirectory.appendingPathComponent("image.jpg", isDirectory: false)
try? data.write(to: imageUrl)
It does work for me: