code: def run(self):
          
          if self.args.roster_cache and os.path.exists(self.args.roster_cache):
              logging.info(u"Loading roster from {0!r}"
                                              .format(self.args.roster_cache))
              try:
                  self.client.roster_client.load_roster(self.args.roster_cache)
              except (IOError, ValueError), err:
                  logging.error(u"Could not load the roster: {0!r}".format(err))
          self.client.connect()
          self.client.run()
docs: Request client connection and start the main loop.