How to test if particular notification is being displayed or if it's dismissed

[omnigenous]

notify-send -t 0 "hello"

# do something if notification is closed by user or if it expires in cases when `-t` is not `0`

I want to detect when particular notification is dismissed/closed but not sure how.

I tried --print-id flag but I don't think that I can use it to kill it.
$! also didn't gave me process id to kill

In hopes to check periodically if process is exists

[bynect]

you could monitor the notification history.

#1348 adds something that may be useful for your use case