title: How to cancel network request with afnetworking
body: <p>Is there a way to cancel all network request (the request started by another method) before I do a network request with AFNetworking
  I tried like below but not work:</p>
  
  <pre><code>- (void)sendRequest:(NSUInteger)page{
  
  
  NSURL *aUrl = [NSURL URLWithString:@"http://www.abc.com/"];
  AFHTTPClient *httpClientToCancel = [[AFHTTPClient alloc] initWithBaseURL:aUrl];
  [httpClientToCancel cancelAllHTTPOperationsWithMethod:@"POST" path:@"product/like"];
  [httpClientToCancel release];
  
  ... start a new request here .....
  </code></pre>
  
  <p>But not work. I just want to cancel all request (at least the request I wrote above) before I start a new request.</p>
  
  <p>Thank you!</p>