*/
    public String getProductVersion() {
        return productVersion;
    }

    /**
     * Sets the interval for checking the system CPU load.
     *
     * @param systemCpuCheckInterval The interval in milliseconds.
     */
    public void setSystemCpuCheckInterval(final long systemCpuCheckInterval) {
        this.systemCpuCheckInterval = systemCpuCheckInterval;

        }

        // favorite
        if (fessConfig.isUserFavorite()) {
            ComponentUtil.getUserInfoHelper().storeQueryId(queryId, documentItems);
        }

    }

    /**
     * Internal search method that executes the actual search query.
     *
     * This method performs the search using the rank fusion processor and may retry
     * with OR operator if the hit count is below the configured minimum threshold.