docs: def get_player_achievements(self, steamID, appID, language=None,
              format=None):
          """Request the achievements for a given app and steam id.
  
          steamID: Users steam ID
          appID: The app id
          language: The language to return the results in. None uses default.
          format: Return format. None defaults to json. (json, xml, vdf)
  
          """
          parameters = {'steamid' : steamID, 'appid' : appID}
          if format is not None:
              parameters['format'] = format
          if language is not None:
              parameters['l'] = language
          else:
              parameters['l'] = self.language
          url = self.create_request_url(self.interface, 'GetPlayerAchievements', 1,
              parameters)
          data = self.retrieve_request(url)
          return self.return_data(data, format=format)