private boolean entryAndResponseHaveDateHeader(HttpCacheEntry entry, HttpResponse response) {
    if (entry.getFirstHeader(HTTP.DATE_HEADER) != null
        && response.getFirstHeader(HTTP.DATE_HEADER) != null) {
      return true;
    }

    return false;
  }
  private boolean entryDateHeaderNewerThenResponse(HttpCacheEntry entry, HttpResponse response) {
    try {
      Date entryDate = DateUtils.parseDate(entry.getFirstHeader(HTTP.DATE_HEADER).getValue());
      Date responseDate = DateUtils.parseDate(response.getFirstHeader(HTTP.DATE_HEADER).getValue());

      if (!entryDate.after(responseDate)) {
        return false;
      }
    } catch (DateParseException e) {
      return false;
    }

    return true;
  }