code: private void addCredentials(String accessId) throws Exception {
          temporarySubject = new Subject();
          Hashtable<String, Object> hashtable = new Hashtable<String, Object>();
          hashtable.put(AttributeNameConstants.WSCREDENTIAL_UNIQUEID, AccessIdUtil.getUniqueId(accessId));
          temporarySubject.getPublicCredentials().add(hashtable);
          setWSPrincipal(temporarySubject, username, accessId, WSPrincipal.AUTH_METHOD_CERTIFICATE);
          setCredentials(temporarySubject, username, username);
          temporarySubject.getPublicCredentials().remove(hashtable);
      }
docs: Add unique ID and call setPrincipalAndCredentials
  
  @param accessId
  @throws Exception