assertNull(request.getModel());
        assertNull(request.getMaxTokens());
        assertNull(request.getTemperature());
        assertFalse(request.isStream());
    }

    @Test
    public void test_addMessage() {
        final LlmChatRequest request = new LlmChatRequest();
        final LlmMessage message = LlmMessage.user("Test message");

        final LlmChatRequest result = request.addMessage(message);

        // getMessages() returns a defensive copy for thread-safety
        assertEquals(messages, session.getMessages());
    }

    @Test
    public void test_addMessage() {
        final ChatSession session = new ChatSession();
        final LocalDateTime beforeAdd = session.getLastAccessedAt();

        final ChatMessage message = ChatMessage.userMessage("Hello");