code: public NotificationArea readNotificationArea(InputStream in) throws ConversionException, IOException {
          JSONObject json = parseObject(in);
          NotificationArea ret = new NotificationArea();
          ret.registrationsURL = readStringInternal(json.get(N_REGISTRATIONS));
          ret.serverRegistrationsURL = readStringInternal(json.get(N_SERVERREGISTRATIONS));
          ret.inboxURL = readStringInternal(json.get(N_INBOX));
          ret.clientURL = readStringInternal(json.get(N_CLIENT));
          return ret;
      }
docs: Decode a JSON document to retrieve a NotificationArea instance.
  
  @param in The stream to read JSON from
  @return The decoded NotificationArea instance
  @throws ConversionException If JSON uses unexpected structure/format
  @throws IOException If an I/O error occurs or if JSON is ill-formed.
  @see #writeNotificationArea(OutputStream, NotificationArea)