[lime-users] How to use Pirania in Libremesh?

Hi all, is there any guide how to use pirania? I'd like to use a voucher based Network access in the Nighbourhood - and found pirania in the lime packages. It tells something about the CLI /usr/bin/voucher and some commands - but not what those commands expect. Has someone kind of an example oder manual? Thank you and regards, Andy