|The identifier for a registered activation group serves several
- identifies the group uniquely within the activation system, and
- contains a reference to the group's activation system so that the
group can contact its activation system when necessary.
ActivationGroupID is returned from the call to
ActivationSystem.registerGroup and is used to identify
the group within the activation system. This group id is passed
as one of the arguments to the activation group's special constructor
when an activation group is created/recreated.