websocket chat python file

[Bechma]

I'm learning about how to implement web sockets with actix and I was looking at the example linked from here:

I understand the example, it's clear and I understand everything, but I don't get why is this python file there, I got 404 everytime that I run it :/ https://github.com/actix/examples/blob/master/websockets/chat/client.py