Basically, this test will connect to websocket based on the ip address of this URL. For example, http://192.168.4.1 is hosting this website, then once you access this website, it'll connect to 192.168.4.1/d/ws/issue websocket. Also it checks for basic things like is this is http, ws or wss.
Once connected, it'll display whenever the websocket server sends somethg. it'll show on your console and write into id=person. It'll be writing the letter 'e'. That's all. You can change the program however you like.