public Map convert(RestError re) {
    Map<String, Object> m = createMap();
    HttpStatus status = re.getStatus();
    m.put(getStatusKey(), status.value());

    int code = re.getCode();
    if (code > 0) {
      m.put(getCodeKey(), code);
    }

    String message = re.getMessage();
    if (message != null) {
      m.put(getMessageKey(), message);
    }

    String devMsg = re.getDeveloperMessage();
    if (devMsg != null) {
      m.put(getDeveloperMessageKey(), devMsg);
    }

    String moreInfoUrl = re.getMoreInfoUrl();
    if (moreInfoUrl != null) {
      m.put(getMoreInfoUrlKey(), moreInfoUrl);
    }

    return m;
  }