self_alias => The alias of the invoking resultset
foreign_alias => The alias of the to-be-joined resultset (does *NOT* always match rel_name)
+ # only one of these (or none at all) will ever be supplied to aid in the
+ # construction of a join-free condition
self_resultobj => The invocant object itself in case of a $resultobj->$rel_name() call
+ foreign_resultobj => The related object in case of $resultobj->set_from_related($rel_name, $foreign_resultobj)
# deprecated inconsistent names, will be forever available for legacy code
self_rowobj => Old deprecated slot for self_resultobj