Function session_is_live 

pub fn session_is_live() -> bool

Whether the work running here belongs to the account currently on screen.

There is exactly one UI, showing one account. A task bound to a previous account keeps working correctly — its database, its chats, its client — but what it produces must not be painted into the account the user is now looking at. Every emission asks this, which is why almost none of them has to ask it by hand.