/**
     * Creates a new chat session.
     *
     * @param userId the user ID (can be null for anonymous users)
     * @return the created session
     */
    public ChatSession createSession(final String userId) {
        final ChatSession session = new ChatSession(userId);
        sessionCache.put(session.getSessionId(), session);
        if (logger.isDebugEnabled()) {

                    return "full";
                }
                return defaultValue;
            }
        });

        final ChatSession session = new ChatSession();
        session.addUserMessage("Q1");
        session.addAssistantMessage("A1");
        session.addUserMessage("Q2");
        session.addAssistantMessage("A2");