Problem with DictDB : cannot iterate

As you may know, the DictDB type doesn’t seem iterable with a for ... in loop, contrary to a classic Python dict.

Indeed, let’s say I instantiate a DictDB in my IconScoreBase herited class like that :

self._dict = DictDB('DICT', db, value_type=int)

Then, I create an external method for adding items to that DictDB :

@external
def create_item(self, key: str, value: int) -> None:
    self._dict[key] = value

Finally, I create a method that reads all the values of such dict, and return it :

@external(readonly=True)
def get_items(self) -> list:
    items = []
    for item in self._dict:
        items.append(item)
    return items

The function get_items won’t work - at least not in tbears, either in Yeouido ; the method never returns any valid result but instead starts an infinite loop.
EDIT: It actually stopped Yeouido from working at 2020-03-01 01:56:51 (UTC+1) after calling that method. Sorry for that.

My current solution to this problem is the following :
As (key, value) pairs aren’t iterable in DictDB, I keep an ArrayDB next to the DictDB that keeps all keys of that DictDB. As ArrayDB are iterable, I can iterable through my DictDB using all the keys in the ArrayDB.
Link to the actual implementation of my current “IterableDictDB” : https://github.com/iconation/iconswap-SCORE/blob/master/ICONSwap/iterable_dict_db.py

Full source code of buggy dictDB SCORE : https://github.com/iconation/DictDBTesting/blob/master/IterableDictDB/main.py