code: public static void insertUser(String username, boolean isSuper) throws RequestExecutionException
      {
          QueryProcessor.process(String.format("INSERT INTO %s.%s (name, super) VALUES ('%s', %s)",
                                               AUTH_KS,
                                               USERS_CF,
                                               escape(username),
                                               isSuper),
                                 consistencyForUser(username));
      }
docs: Inserts the user into AUTH_KS.USERS_CF (or overwrites their superuser status as a result of an ALTER USER query).
  
  @param username Username to insert.
  @param isSuper User's new status.
  @throws RequestExecutionException