assertEquals("B1", dataMap.get("b"));
    }

    /** Case 2: Key conflict (without .overwrite) → Overwrite with value from responseDataMap */
    @Test
    public void test_mergeResponseData_keyConflict() {
        Map<String, Object> dataMap = new HashMap<>();
        dataMap.put("x", "X0");
        Map<String, Object> responseDataMap = new HashMap<>();
        responseDataMap.put("x", "X1");