def id2token(id_lists, map_id_to_token):
    """ transform tokens to ids

    Args:
        token_lists: List[List[int]] -> input list of lists
        map_token_to_id: dict
    Returns:
        ids: List[List[char]]
    """
    tokens = []
    for ids in id_lists:
        tokens.append([map_id_to_token[i] for i in ids])
    return tokens