code: def runserver(host=None, port=None):
      
      host = host or os.getenv('HTTP_HOST', '0.0.0.0')
      port = port or os.getenv('HTTP_PORT', '9001')
      zioloop = ioloop.IOLoop.instance()
  
      # setup pika client:
      pc = QueueManager(zioloop)
      app.pc = pc
      pc.connect()
      app.listen(port, host)
      zioloop.start()
docs: Run Tornado server