*
     * @return the engine information
     * @throws SearchEngineClientException if the client is not an HttpClient
     */
    public EngineInfo getEngineInfo() {
        if (client instanceof final HttpClient httpClient) {
            return httpClient.getEngineInfo();
        }
        throw new SearchEngineClientException("client is not HttpClient.");
    }

    //
    // Fesen Client
    //