New Membership Service, Authentication example on jxta homepage doesn't work

Hello everyone!
I'm trying to implement a new Membership Service, which doesn't only
check for the password and login, but also some additional data. Only
if the data fits certain criterias, the peer should be able to join
the group. I tried to extend the example of the SecurePeerGroup
example provided on the jxta homepage (which has compilation errors).
To get the credentials the example does:

AuthenticationCredential authCred =new AuthenticationCredential(
satellaPeerGroup, null, creds )

which would mean, no authentication method. Leaving it like that, I
can join the group even with wrong password and login. Probably the
standard membership service is still active.
If I however change the method (second parameter) to
"PasswdAuthentication" as mentioned in the example, I always get an
exception telling me that the method doesn't exist. What can I do? Any
suggestions?

Does anyone has a working version of a authentication example which I
could build on?

Regards,
Vinh