How to use the jsondiff.JsonDiffer function in jsondiff

def test_marshal(self):
        differ = JsonDiffer()

        d = {
            delete: 3,
            '$delete': 4,
            insert: 4,
            '$$something': 1
        }

        dm = differ.marshal(d)

        self.assertEqual(d, differ.unmarshal(dm))

def test_compact_syntax(self, scenario):
        a, b = scenario
        differ = JsonDiffer(syntax='compact')
        d = differ.diff(a, b)
        self.assertEqual(b, differ.patch(a, d))
        dm = differ.marshal(d)
        self.assertEqual(d, differ.unmarshal(dm))

def test_symmetric_syntax(self, scenario):
        a, b = scenario
        differ = JsonDiffer(syntax='symmetric')
        d = differ.diff(a, b)
        self.assertEqual(b, differ.patch(a, d))
        self.assertEqual(a, differ.unpatch(b, d))
        dm = differ.marshal(d)
        self.assertEqual(d, differ.unmarshal(dm))

sync_index_pattern = load_kibana_index_pattern(path)

    # load generated index pattern
    gen_index_pattern = json.load(args.gen_index_pattern)["objects"][0]
    gen_index_pattern["attributes"].pop("title")  # detects title set in sync'd pattern

    # decode fields, they are json
    sync_index_pattern["attributes"]["fields"] = json.loads(sync_index_pattern["attributes"].pop("fields"))
    gen_index_pattern["attributes"]["fields"] = json.loads(gen_index_pattern["attributes"].pop("fields"))

    exit_val = 0
    exit_val = max(exit_val, iterate(sync_index_pattern["id"], "", gen_index_pattern, sync_index_pattern))

    # double check that there is no difference
    if exit_val == 0:
        d = jsondiff.JsonDiffer(syntax='symmetric').diff(sync_index_pattern, gen_index_pattern)
        if d:
            print("index patterns differ: ", d)
            return 5
        print("up-to-date")

    return exit_val

if len(v1) > 0 and isinstance(v1[0], dict):
            for item in v1:
                qkey = find_key(item)
                if qkey == "":
                    print("Script is missing type to compare {}".format(item))
                    return 3

                item2 = find_item(v2, qkey, item[qkey])
                ret_val = max(ret_val, iterate(val_id, build_key(key, "{}={}".format(qkey, item[qkey])), item, item2,
                                               apm_v1=apm_v1))
        else:
            v1, v2 = sorted(v1), sorted(v2)
            for item1, item2 in zip(v1, v2):
                ret_val = max(ret_val, iterate(val_id, key, *json_val(item1, item2), apm_v1=apm_v1))
    else:
        d = jsondiff.JsonDiffer(syntax='symmetric').diff(*json_val(v1, v2))
        if d:
            if key == "attributes.title" or key == "attributes.fields.name=transaction.marks.*.*":
                return ret_val
            ret_val = 2
            print("Difference for id '{}' for key '{}'".format(val_id, key))
            try:
                print(json.dumps(d, indent=4))
            except:
                print(d)
            v1_label, v2_label = "APM Server", "Kibana"
            if not apm_v1:
                v1_label, v2_label = v2_label, v1_label
            print("Value in {}: {!r}".format(v1_label, v1))
            print("Value in {}: {!r}".format(v2_label, v2))
            print("---")
    return ret_val

def __print_preview(old_json, new_json):
    error_print('\n---------------- Preview (Beta) ----------------')
    if not new_json:
        error_print('\nSource configuration is empty. No changes will be made.')
        return False

    # perform diff operation
    # to simplify output, add one shared key in src and dest configuration
    new_json['@base'] = ''
    old_json['@base'] = ''
    differ = JsonDiffer(syntax='explicit')
    res = differ.diff(old_json, new_json)
    keys = str(res.keys())
    if res == {} or (('update' not in keys) and ('insert' not in keys)):
        error_print('\nTarget configuration already contains all key-values in source. No changes will be made.')
        return False

    # format result printing
    for action, changes in res.items():
        if action.label == 'delete':
            continue  # we do not delete KVs while importing/exporting
        elif action.label == 'insert':
            error_print('\nAdding:')
            for key, adding in changes.items():
                record = {'key': key}
                for attribute, value in adding.items():
                    record[str(attribute)] = str(value)