}

        // Walk from newest turn to oldest, selecting contiguous newest turns that fit within budget
        int remaining = budgetChars;
        int firstIncludedTurn = turns.size();
        for (int t = turns.size() - 1; t >= 0; t--) {
            final int[] turn = turns.get(t);
            int turnLen = 0;
            for (int i = turn[0]; i < turn[1]; i++) {

        final List<LlmMessage> history = new ArrayList<>();
        history.add(LlmMessage.user("Q1")); // standalone turn (2)
        history.add(LlmMessage.user("Q2")); // 2
        history.add(LlmMessage.assistant("A2")); // pair turn (4)
        history.add(LlmMessage.user("Q3")); // standalone turn (2)
        final LlmChatRequest request = new LlmChatRequest();
        client.testAddHistoryWithBudget(request, history, 100);