}

    public void setClusterName(final String clusterName) {
        this.clusterName = clusterName;
    }

    public EngineInfo getEngineInfo() {
        if (client instanceof final HttpClient httpClient) {
            return httpClient.getEngineInfo();
        }
        throw new SearchEngineClientException("client is not HttpClient.");
    }

    //
    // Fesen Client
    //