code: private void setValidity(Object val) throws CertificateException {
          if (!(val instanceof CertificateValidity)) {
              throw new CertificateException(
                               "CertificateValidity class type invalid.");
          }
          interval = (CertificateValidity)val;
      }
docs: Set the validity interval of the certificate.
  
  @params val the Object class value for the CertificateValidity
  @exception CertificateException on invalid data.