code: def get_owned_games(self, steamID, include_appinfo=1,
              include_played_free_games=0, appids_filter=None, format=None):
          
          parameters = {
                      'steamid' : steamID,
                      'include_appinfo' : include_appinfo,
                      'include_played_free_games' : include_played_free_games
                      }
          if format is not None:
              parameters['format'] = format
          if appids_filter is not None:
              parameters['appids_filter'] = appids_filter
          url = self.create_request_url(self.interface, 'GetOwnedGames', 1,
              parameters)
          data = self.retrieve_request(url)
          return self.return_data(data, format=format)
docs: Request a list of games owned by a given steam id.
  
          steamID: The users id
          include_appinfo: boolean.
          include_played_free_games: boolean.
          appids_filter: a json encoded list of app ids.
          format: Return format. None defaults to json. (json, xml, vdf)