code: private void setSubject(Object val) throws CertificateException {
          if (!(val instanceof X500Name)) {
              throw new CertificateException(
                               "Subject class type invalid.");
          }
          subject = (X500Name)val;
      }
docs: Set the subject name of the certificate.
  
  @params val the Object class value for the Subject
  @exception CertificateException on invalid data.