def get_activity_notification_session_for_objective_bank(self, activity_receiver=None, objective_bank_id=None):
raise Unimplemented()<EOL>
Gets the OsidSession associated with the activity notification
        service for the given objective bank.

        arg:    objectiveBankId (osid.id.Id): the Id of the objective
                bank
        return: (osid.learning.ActivityNotificationSession) - an
                ActivityNotificationSession
        raise:  NotFound - objectiveBankId not found
        raise:  NullArgument - activityReceiver or objectiveBankId is
                null
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented - supports_activity_notification() or
                supports_visible_federation() is false
        compliance: optional - This method must be implemented if
                    supports_activity_notification() and
                    supports_visible_federation() are true.