code: public JSONArray names() {
        verifyIsNull();
        JSONArray ja = new JSONArray();
        Iterator keys = keys();
        while( keys.hasNext() ){
           ja.element( keys.next() );
        }
        return ja;
     }
docs: Produce a JSONArray containing the names of the elements of this
  JSONObject.
  
  @return A JSONArray containing the key strings, or null if the JSONObject
  is empty.