public long measureValidationLength(String filename, String signature) {
   Wget wget = new Wget();
   long startTime = (new Date()).getTime();
   wget.wget(toUrl(filename, signature));
   long endTime = (new Date()).getTime();
   long took = endTime - startTime;
   // System.out.println(page);
   return took;
 }
  public boolean isValidMac(String filename, String signature) {
    Wget wget = new Wget();
    String page = wget.wget(toUrl(filename, signature));

    System.out.println(page);

    boolean isValid = page.contains("validity: true");
    return isValid;
  }