code: def emit(self, event, data=None, room=None, include_self=True,
               namespace=None, callback=None):
          
          return self.socketio.emit(event, data, room=room,
                                    include_self=include_self,
                                    namespace=namespace or self.namespace,
                                    callback=callback)
docs: Emit a custom event to one or more connected clients.