>>>>> "gsu" == gsu  <gsu@UU.NET> writes:

    gsu> Returning an error would certainly be much cleaner than a
    gsu> null pointer reference.  I was so puzzled that I checked the
    gsu> API guide and my code repeatly.  If no implementation is
    gsu> intended, why advertise it in the guide?

An implementation is intended.  The API guide in doc/api does not
particularly correspond to the source code.  We do not really have API
documentation to speak of at this time.

    gsu> So there is no way that I can remove any expired credential?

Correct, but it is probably not a major problem; expired credentials
will not be used.  If your cache is getting too full, remove all the
credentials and get a new TGT.