title: Http/2 server_push with NSURLSession
body: <p>I have implemented a program to communicate http2 using NSURLSession of iOS9, And it can communicate with my server in http2.
  However, I'm having a problem with receive <a href="https://www.rfc-editor.org/rfc/rfc7540#section-8.2" rel="nofollow noreferrer">server_push</a>.
  I found ENABLE_PUSH value is 0 in their settings and there's no delegate in receive server push in NSURLSession...</p>
  <p>・I think NSURLSession doesn't support server_push. Is this right?</p>
  <p>・If it support server_push,how to use?</p>
  <pre><code>/**
  It WORKS for post data and get response.
  I don't know the code should be added here 
  in order to get the server_push.
  I suspect that NSURLSession itself cannot receive the server_push(;_;)
  **/
  - (void) postData
  {
       NSString *urlstr = self.urlArea.text;
       NSURL * url = [NSURL URLWithString:urlstr];
       NSDictionary *params = @{@&quot;data&quot;:@&quot;&quot;};
      //json to query
      NSData *query = [self buildQueryWithDictionary: params];
  
      //make request
      NSMutableURLRequest *request = [NSMutableURLRequest
                                  requestWithURL:url
                                  cachePolicy: NSURLRequestReloadIgnoringCacheData
                                  timeoutInterval: 10.0];
      [request setHTTPMethod: @&quot;POST&quot;];
      [request setHTTPBody: query];
  
      //prepare session
      NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[NSOperationQueue mainQueue]];
  
      //resume
       [[session dataTaskWithRequest: request  completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
      {
          if (response &amp;&amp; ! error) {
               NSLog(@&quot;Data: %@&quot;, [[NSString alloc] initWithData: data  encoding: NSUTF8StringEncoding]);
          }else {
              NSLog(@&quot;ERR: %@&quot;, error);
          }
      }] resume];
  }
  </code></pre>