title: NSJSONSerialization and NSNull
body: <p>Occasionally I encounter JSON structure like "'data': null". NSJSONSerialization turns those into NSNull, which is, to be honest quite annoying.</p>
  
  <p>I understand the reason behind this - things like NSDictionary cannot contain nil value.</p>
  
  <p>That's fine, however in those cases, I would rather see the element missing from the de-serialized data structure, which in many cases actually ease the handling. Is there an option or configuration that can be passed to NSJSONSerialization, and ask it to do exactly this - simply miss those nil's in the de-serialized data structure? </p>