*
     * @param request the chat request
     * @return the chat response
     * @throws LlmException if too many concurrent requests or interrupted
     */
    protected LlmChatResponse chatWithConcurrencyControl(final LlmChatRequest request) {
        if (concurrencyLimiter == null) {
            return chat(request);
        }
        if (logger.isDebugEnabled()) {