history.add(LlmMessage.user("Hi")); // 2 chars
        history.add(LlmMessage.assistant("Hello")); // 5 chars
        final LlmChatRequest request = new LlmChatRequest();
        client.testAddHistoryWithBudget(request, history, 100);
        assertEquals(2, request.getMessages().size());
        assertEquals("Hi", request.getMessages().get(0).getContent());