async def METHOD_NAME(user_id, corpora):
    with plugins.runtime.DB as db:
        curr_list = await db.get(mk_list_key(user_id))
        for corp in corpora:
            if corp not in curr_list:
                curr_list.append(corp)
            else:
                print(('Corpus {0} already present, skipping.'.format(corp)))
        await db.set(mk_list_key(user_id), curr_list)