*
     * @param key the parameter key
     * @param value the parameter value
     * @return this request for method chaining
     */
    public LlmChatRequest putExtraParam(final String key, final String value) {
        if (extraParams == null) {
            extraParams = new HashMap<>();
        }
        extraParams.put(key, value);
        return this;
    }

    /**