def METHOD_NAME(self, aid):
    """
    Tranlates an aid (anidb.info anime id) to tvdbid (thetvdb.com).
    :param aid: The aid in int or string
    :return: One tvdbid as string, or None.
    """
    if not self._xml_list:
        self._xml_list = self._load_xml(ANIME_LIST_URL)
    anime = self._xml_list.find(".//anime[@anidbid='{aid}']".format(aid=aid))
    return anime.attrib.get('tvdbid') if anime else None