* @return the chat result with session info, sources, and HTML content
     */
    public ChatResult streamChatEnhanced(final String sessionId, final String userMessage, final String userId,
            final ChatPhaseCallback callback) {
        return streamChatEnhanced(sessionId, userMessage, userId, Collections.emptyMap(), new String[0], callback);
    }

    /**

        streamChatWithConcurrencyControl(request, callback);
    }

    /**
     * Generates a direct answer without document search.
     * This method is currently not called from the streamChatEnhanced() flow,
     * but is provided as an extension point for future DIRECT_ANSWER intent support.
     */
    @Override