* @throws LlmException if LLM is not available
     */
    public void generateDocumentNotFoundResponse(final String userMessage, final String documentUrl, final List<LlmMessage> history,
            final LlmStreamCallback callback) {
        if (logger.isDebugEnabled()) {
            logger.debug("[LLM] Delegating generateDocumentNotFoundResponse. llmType={}", getLlmType());
        }

     * @param userMessage the user's message
     * @param documentUrl the URL that was not found
     * @param history the conversation history
     * @param callback the streaming callback
     */
    void generateDocumentNotFoundResponse(String userMessage, String documentUrl, List<LlmMessage> history, LlmStreamCallback callback);

    /**
     * Generates a summary of the specified documents.
     *

        applyPromptTypeParams(request, "noresults");
        request.setStream(true);

        streamChatWithConcurrencyControl(request, callback);
    }

    @Override
    public void generateDocumentNotFoundResponse(final String userMessage, final String documentUrl, final List<LlmMessage> history,
            final LlmStreamCallback callback) {
        final LlmChatRequest request = new LlmChatRequest();

                    phaseStartTime = System.currentTimeMillis();
                    callback.onPhaseStart(ChatPhaseCallback.PHASE_ANSWER, "Generating response...");
                    llmClientManager.generateDocumentNotFoundResponse(userMessage, documentUrl, history, (chunk, done) -> {
                        fullResponse.append(chunk);
                        callback.onChunk(chunk, done);
                    });