assertEquals(1, request.getMessages().size());
        assertEquals(200, request.getMessages().get(0).getContent().length());
    }

    @Test
    public void test_addHistoryWithBudget_exactBudget() {
        // Total chars exactly equals budget
        final List<LlmMessage> history = new ArrayList<>();
        history.add(LlmMessage.user("AAAA")); // 4