assertEquals("Z1", dataMap.get("z"));
    }

    /** Case 5: Overwrite processing for multiple fields, existing overwrite keys are also properly removed */
    public void test_mergeResponseData_multipleOverwrite() {
        Map<String, Object> dataMap = new HashMap<>();
        // Case where the initial dataMap also contains overwrite keys
        dataMap.put("m", "M0");
        dataMap.put("n.overwrite", "N0_old");