valid = new Boolean(result);
valid = Boolean.valueOf(result);
  public boolean selfTest()  {    if (valid == null)      {        boolean result = super.selfTest(); // do symmetry tests        if (result)          {            result = testKat(KAT_KEY, KAT_CT, KAT_PT);          }        valid = new Boolean(result);      }    return valid.booleanValue();  }