[CentOS] find leave packages at CentOS-8

Sun Feb 2 07:59:31 UTC 2020
d tbsky <tbskyd at gmail.com>

Hi:
    I use to find all the leave packages with "package-cleanup
--leaves --all". but the "--all" parameter no longer valid under
CentOS-8. is there alternative command I can use to find out all the
leave packages?