title: NSMutableData to NSDictionary returning null
body: <p>I'm writing a program that uses the Instagram API and I'm running into some issues with <code>NSMutableData and NSDictionary.</code></p>
  
  <p>Since I have to make multiple calls to the API, I decided to create a <code>NSMutableData object</code>, append smaller NSData objects to it and then turn the whole thing into an NSDictionary.</p>
  
  <p>However, after I make a second call to <code>NSMutableData appendData NSData,</code> when I turn <code>NSMutableData</code> into an <code>NSDictionary</code>, the dictionary returns null.</p>
  
  <p>Here's some of my code.</p>
  
  <pre><code>NSMutableData *userData = [[NSMutableData alloc]init]
  NSData *feed = [NSData dataWithContentsOfURL:[NSURL URLWithString:[NSString   stringWithFormat:@"https://api.instagram.com/v1/users/17636367/media/recent?access_token=%@",accessToken]]];
  [userData appendData:feed];
  NSData *moarData = [NSData dataWithContentsOfURL:[NSURL URLWithString:[NSString stringWithFormat:@"https://api.instagram.com/v1/users/17636367/media/recent?access_token=%@&amp;max_id=%@",accessToken, maxID]]];
  [userData appendData:moarData];
  NSDictionary *dictTwo = [NSJSONSerialization JSONObjectWithData:userData options:NSJSONReadingMutableContainers error:nil];
  NSLog(@"%@",dictTwo);
  </code></pre>
  
  <p>dictTwo returns null. However, when I make only one call to appendData, the dictionary isn't empty.</p>
  
  <p>Thanks.</p>