code: def start(self):
          
          if self.running:
              raise Exception('Advertiser is already running')
          if self.io_loop is None:
              self.io_loop = tornado.ioloop.IOLoop.current()
  
          self.running = True
          answer = tornado.gen.Future()
          self._schedule_ad(0, answer)
          return answer
docs: Starts the advertise loop.
  
          Returns the result of the first ad request.