[erlang-questions] How do I tell whether a process is using proc_lib?

[Roger Lipscombe]

Specifically, if I call sys:get_state(Pid) on a process that's not
using proc_lib, and that process doesn't deal with {system, get_state}
messages, it'll crash with a case_clause in loop (or whatever).

This is a bad thing. Can I tell that a process is a proc_lib process
(or a gen_server, gen_fsm, etc.) before accidentally killing it?

Thanks,
Roger.