How to tell jenkins to use a PID file

While trying to monitor jenkins with monit, I was looking for a pid file.
I saw one, but it seems not to be used. File date wasnt too old, so I am confused.
I also dont find any up2date reference to pid in the wiki, so I want to ask
if pid support has been removed in a recent release?
there is something in the windows-service folder in git, and some deb script for init.d,
but I cant find any recent information. The jenkins script in /usr/bin/jenkins also doesnt help,
and there is no hint in jenkins.service.
So, if it is possible to tell jenkins to create a pidfile?

Jenkins now manages its services with systemd. It does not require a pid file and does not create a pid file.

See this superuser answer for suggestions on how to use monit with services that are managed by systemd: