How to run multiple NSURLSessionDownloadTask's so I can download multiple user photo streams from Instagram?

    //  ViewController.swift
    //  Fashun
    //
    //  Created by Alex Macleod on 20/10/14.
    //  Copyright (c) 2014 Alex Macleod. All rights reserved.
    //

    import UIKit

    class ViewController: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {

    var collectionView: UICollectionView?

    var instanceOfCustomObject: CustomObject = CustomObject()
    var accessToken: NSString!
    var userDefaults: NSUserDefaults!
    let colorWheel = ColorWheel()
    var photoCount: Int! = 0
    let photos = NSMutableArray()

    override func viewDidLoad() {
        super.viewDidLoad()

        userDefaults = NSUserDefaults.standardUserDefaults()
        self.accessToken = userDefaults!.objectForKey("accessToken") as NSString
        println(self.accessToken)

    //        instanceOfCustomObject.someProperty = "Hello World"
    //        var accessToken : NSString? = NSString(instanceOfCustomObject.accessToken)
    //        println(accessToken)
    //        instanceOfCustomObject.authorize()

    // Do any additional setup after loading the view, typically from a nib.
        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
    //        layout.sectionInset = UIEdgeInsets(top: 20, left: 0, bottom: 0, right: 0)
        layout.itemSize = CGSize(width: 124, height: 124)
        layout.minimumInteritemSpacing = 1.0
        layout.minimumLineSpacing = 1.0
        collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
        collectionView!.dataSource = self
        collectionView!.delegate = self
        collectionView!.registerClass(Cell.self, forCellWithReuseIdentifier: "Cell")
        collectionView!.backgroundColor = UIColor.whiteColor()
        self.view.addSubview(collectionView!)

        getData()
    }

        func getData() -> Void {
            let baseUrl = NSURL(string:"https://api.instagram.com/v1/users/7522782/media/recent/?access_token=\(self.accessToken)")

    //        let forcastUrl = NSURL(string: "37.8267,-122.423", relativeToURL: baseUrl)

            //        let data = NSData(contentsOfURL: forcastUrl)
            //        println(data)
            let sharedSession = NSURLSession.sharedSession()
            let downloadTask: NSURLSessionDownloadTask = sharedSession.downloadTaskWithURL(baseUrl!, completionHandler: { (location: NSURL!, response: NSURLResponse!, error: NSError!) -> Void in


                //            var urlContents = NSString.stringWithContentsOfURL(location, encoding: NSUTF8StringEncoding, error: nil)
                //            println(urlContents)

                let dataObject = NSData(contentsOfURL: baseUrl!)

                if (error == nil) {
                    let responseDictionary: NSDictionary = NSJSONSerialization.JSONObjectWithData(dataObject!, options: nil, error: nil) as NSDictionary
    //                println(responseDictionary)

                    var currentResponse = responseDictionary.valueForKeyPath("data.images.standard_resolution.url") as NSArray



                    dispatch_async(dispatch_get_main_queue(), { () -> Void in

    //                    for url in currentResponse {
    //                        var urlStrings: NSString = url as NSString
    //                        
    //                        var images =  UIImage(data: NSData(contentsOfURL: NSURL(string:urlStrings)!)!)
    //
    //                    }
                        for url in currentResponse {
                            var urls: NSString = url as NSString
                            //                        println(images)
                            var photoUrls = NSURL(string: urls)

                            var err: NSError?
                            var imageData :NSData = NSData(contentsOfURL: photoUrls!,options: NSDataReadingOptions.DataReadingMappedIfSafe, error: &err)!
                            self.photos.addObject(UIImage(data:imageData)!)
                            println(self.photos)
                        }

                        self.photoCount = currentResponse.count as Int

                        self.collectionView?.reloadData()

                    })

                } else {

                    let networkIssueController = UIAlertController(title: "Error", message: "Something went wrong get a better phone you pleb!", preferredStyle: .ActionSheet)
                    let okButton = UIAlertAction(title: "OK", style: .Default, handler: nil)
                    networkIssueController.addAction(okButton)
                    let cancelButton = UIAlertAction(title: "Cancel", style: .Cancel, handler: nil)
                    networkIssueController.addAction(cancelButton)

                    self.presentViewController(networkIssueController, animated: true, completion: nil)

                    dispatch_async(dispatch_get_main_queue(), { () -> Void in
                        //Stop refresh animation


                    })
                }
            })

            downloadTask.resume()

        }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return photoCount

    }

    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as Cell
    //                println(photos)
    //            cell.textLabel.text = "Text"
        cell.imageView.image = photos.objectAtIndex(indexPath.row) as? UIImage
    //    cell.photo = self.photos[indexPath.row] as? NSDictionary
        cell.imageView.backgroundColor = colorWheel.randomColor()

        return cell
    }
    }