[Dovecot] Any way to test a master user's password?

Hello,

Is there any way to easily check a master user's password, for itself, without having to refer to another user or to weak the security by allowing master users to log in for themselves?

For example, this works:

# doveadm auth test 'someuser*masteruser'
Password: <enter master user's password here>
passdb: someuser*masteruser auth succeeded

but depends on the existence of another user, and is thus contingent and unnecessarily heavy.

TIA, Axel