Tagging clients in SSE

I am not sure if this is right repo to file an issue. So, if I need to move to actix-web-lab then do let me know.

In example there is code to create new client and broadcast message to all clients. Is there any way to I can attach unique id to clients? So, at the time of broadcast I can pick and choose clients where I need to send message. Any pointers would be really useful. Let me know if my question is not clear.