title: multiple download NSURLSession
body: <p>I have a program that download a video from a url using NSURLSession, but i'm not able to do multiple download at the same time.
  How can i do it?
  How can i manage multiple simultaneous download?</p>
  
  <pre><code>    NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration    defaultSessionConfiguration];
  
      NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfig delegate:self delegateQueue:nil];
  
      NSURLSessionDownloadTask *getVideo = [session downloadTaskWithURL:fileURL
                                                      completionHandler:^(NSURL *location,
                                                                          NSURLResponse *response,
                                                                          NSError *error) {
                                                          // 2
                                                          receivedData = [NSData dataWithContentsOfURL:location];
                                                          dispatch_async(dispatch_get_main_queue(), ^{
                                                              // do stuff with image
                                                               NSLog(@"%s receiveData:%d",__FUNCTION__,[receivedData length]);
                                                          });
                                                      }];
      [getVideo resume];
  </code></pre>