class RequestKey {

  @Override
  public String toString() {
    return String.format("Request [%s %s: %s headers and %s]", method, url,
        headers == null ? "without" : "with " + headers,
        charset == null ? "no charset" : "charset " + charset);
  }

  private  RequestKey(Builder builder);
  private  RequestKey(Request request);

}