def dict_is_all_none(dict_item: dict) -> bool:
    """
    Test if all dictionary items are None.

    :param dict_item: A dictionary object to be testes.
    :return bool: True if all keys have None as value, False otherwise
    """
    for _key, _value in dict_item.items():
        if _value is not None:
            return False
    return True