final Builder builder = Settings.builder()
                .putList("http.hosts", hosts)
                .put("processors", fessConfig.getCrawlerHttpProcessors())
                .put("http.heartbeat_interval", fessConfig.getFesenHeartbeatInterval());
        final String username = fessConfig.getFesenUsername();
        final String password = fessConfig.getFesenPassword();

     */
    public long getHeartbeatInterval() {
        return heartbeatInterval;
    }

    /**
     * Sets the heartbeat interval.
     *
     * @param heartbeatInterval the heartbeat interval in milliseconds
     */
    public void setHeartbeatInterval(long heartbeatInterval) {
        this.heartbeatInterval = heartbeatInterval;
    }

    /**