title: JSONRequestOperationWithRequest issue from the AFNetWorking
body: <p>I am doing a reading on the AFNetworking project and I am being stuck at this point:</p>
  
  <pre><code>(AFJSONRequestOperation *)JSONRequestOperationWithRequest:(NSURLRequest *)urlRequest
                                                      success:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, id JSON))success 
                                                      failure:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON))failure
  </code></pre>
  
  <p>Can someone tell me what this method does and what the parameters (with ^ at front of each) are?</p>