code: def update(data, id, medium, credentials):
      
      _op(data, id, medium, tokens.Operations.UPDATE, credentials)
docs: Updates the [medium] with the given id and data on the user's [medium]List.
      :param data   The data for the [medium] to update.
      :param id     The id of the data to update.
      :param medium Anime or manga (tokens.Medium.ANIME or tokens.Medium.MANGA).
      :raise ValueError For bad arguments.