code: def create_app(cls, port):
          
          app = FrontEndApp()
          app_server = GeventServer(app, port=port, hostname='0.0.0.0')
          return app_server
docs: Create a new instance of FrontEndApp that listens on port with a hostname of 0.0.0.0
  
          :param int port: The port FrontEndApp is to listen on
          :return: A new instance of FrontEndApp wrapped in GeventServer
          :rtype: GeventServer