How to use the deepdiff.helper.KEY_TO_VAL_STR.format function in deepdiff

def _prep_number(self, obj):
        type_ = "number" if self.ignore_numeric_type_changes else obj.__class__.__name__
        if self.significant_digits is not None:
            obj = self.number_to_string(obj, significant_digits=self.significant_digits,
                                        number_format_notation=self.number_format_notation)
        return KEY_TO_VAL_STR.format(type_, obj)

# data is read from files that were previousely written from python and
            # to be consistent with on-screen representation of numbers.
            # Other options would be abs(t1-t2)<10**-self.significant_digits
            # or math.is_close (python3.5+)
            # Note that abs(3.25-3.251) = 0.0009999999999998899 < 0.001
            # Note also that "{:.3f}".format(1.1135) = 1.113, but "{:.3f}".format(1.11351) = 1.114
            # For Decimals, format seems to round 2.5 to 2 and 3.5 to 4 (to closest even number)
            t1_s = self.number_to_string(level.t1,
                                         significant_digits=self.significant_digits,
                                         number_format_notation=self.number_format_notation)
            t2_s = self.number_to_string(level.t2,
                                         significant_digits=self.significant_digits,
                                         number_format_notation=self.number_format_notation)

            t1_s = KEY_TO_VAL_STR.format(t1_type, t1_s)
            t2_s = KEY_TO_VAL_STR.format(t2_type, t2_s)
            if t1_s != t2_s:
                self.__report_result('values_changed', level)

def prepare_string_for_hashing(obj, ignore_string_type_changes=False, ignore_string_case=False):
    """
    Clean type conversions
    """
    original_type = obj.__class__.__name__
    if isinstance(obj, bytes):
        obj = obj.decode('utf-8')
    if not ignore_string_type_changes:
        obj = KEY_TO_VAL_STR.format(original_type, obj)
    if ignore_string_case:
        obj = obj.lower()
    return obj

def _prep_dict(self, obj, parent, parents_ids=EMPTY_FROZENSET, print_as_attribute=False, original_type=None):

        result = []

        key_text = "%s{}".format(INDEX_VS_ATTRIBUTE[print_as_attribute])
        for key, item in obj.items():
            key_formatted = "'%s'" % key if not print_as_attribute and isinstance(key, strings) else key
            key_in_report = key_text % (parent, key_formatted)

            key_hash = self._hash(key, parent=key_in_report, parents_ids=parents_ids)
            item_id = get_id(item)
            if (parents_ids and item_id in parents_ids) or self._skip_this(item, parent=key_in_report):
                continue
            parents_ids_added = add_to_frozen_set(parents_ids, item_id)
            hashed = self._hash(item, parent=key_in_report, parents_ids=parents_ids_added)
            hashed = KEY_TO_VAL_STR.format(key_hash, hashed)
            result.append(hashed)

        result.sort()
        result = ';'.join(result)
        if print_as_attribute:
            type_ = original_type or type(obj)
            type_str = type_.__name__
            for type_group in self.ignore_type_in_groups:
                if self.type_check_func(type_, type_group):
                    type_str = ','.join(map(lambda x: x.__name__, type_group))
                    break
        else:
            type_str = 'dict'
        return "%s:{%s}" % (type_str, result)

parents_ids_added = add_to_frozen_set(parents_ids, item_id)
            hashed = self._hash(item, parent=parent, parents_ids=parents_ids_added)
            # counting repetitions
            result[hashed] += 1

        if self.ignore_repetition:
            result = list(result.keys())
        else:
            result = [
                '{}|{}'.format(i, v) for i, v in result.items()
            ]

        result = sorted(map(str, result))  # making sure the result items are string and sorted so join command works.
        result = ','.join(result)
        result = KEY_TO_VAL_STR.format(type(obj).__name__, result)

        return result

def __get_clean_to_keys_mapping(self, keys, level):
        result = {}
        for key in keys:
            if self.ignore_string_type_changes and isinstance(key, bytes):
                clean_key = key.decode('utf-8')
            elif isinstance(key, numbers):
                type_ = "number" if self.ignore_numeric_type_changes else key.__class__.__name__
                clean_key = self.number_to_string(key, significant_digits=self.significant_digits,
                                                  number_format_notation=self.number_format_notation)
                clean_key = KEY_TO_VAL_STR.format(type_, clean_key)
            else:
                clean_key = key
            if clean_key in result:
                logger.warning(('{} and {} in {} become the same key when ignore_numeric_type_changes'
                                'or ignore_numeric_type_changes are set to be true.').format(
                                    key, result[clean_key], level.path()))
            else:
                result[clean_key] = key
        return result