code for parsing the correct parent_release tag

                        json_of_test_case["config_id"] = "CF_01"

                    # upgrade the version and add the reference in square brackets

                    json_of_test_case["reference"] = re.sub(r"V1.3.1 \[\]", "V1.5.1 [1]", json_of_test_case["reference"])

                    # now for each permutation inside this test case, create the permutation's correct parent_release

                    if "test_cases" in json_of_test_case:

                        # grab everything that is a permutation_body inside the "sub" test_cases,

                        for permutation_body in json_of_test_case["test_cases"]:

                            # default parent release

                            parent_release = "v1.3.1"

                            for tag in permutation_body["tags"]:

                                if tag.startswith('since_'):

                                    parts = tag.split('_')

                                    # the suffix

                                    parent_release = parts[-1]

                            permutation_body["permutation_parent_release"] = parent_release

                    else:

                        print("NO PERMUTATIONS in TESTCASE??? " + json_of_test_case["tp_id"])

                        exit(1)

                testcases.append(json_of_test_case)

    print()