#vulnerable code 
                                @Override
    public Future<JsonArray> groupAsync(final String sigma) {
        /*
         * Build condition of `sigma`
         */
        final JsonObject condition = new JsonObject();
        condition.put(KeField.SIGMA, sigma);
        /*
         * Permission Groups processing
         */
        return Ux.Jooq.on(SPermissionDao.class)
                .countByAsync(condition, "group", "identifier");
    } 
                            #location 12 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public Future<JsonArray> groupAsync(final String sigma) {
        /*
         * Build condition of `sigma`
         */
        final JsonObject condition = new JsonObject();
        condition.put(KeField.SIGMA, sigma);
        /*
         * Permission Groups processing
         *「Upgrade」
         * Old method because `GROUP` is in S_PERMISSION
         * return Ux.Jooq.on(SPermissionDao.class).countByAsync(condition, "group", "identifier");
         * New version: S_PERM_SET processing
         */
        return Ux.Jooq.on(SPermSetDao.class).fetchJAsync(condition);
    }