def setActivities(self, *args, **kwargs):
        def activityDate(activity):
            try:
                return activity['activity']['timestamp']
            except KeyError as kerr:
                return None
        try:
            activities = self.mambuactivitiesclass(groupId=self['encodedKey'], *args, **kwargs)
        except AttributeError as ae:
            from .mambuactivity import MambuActivities
            self.mambuactivitiesclass = MambuActivities
            activities = self.mambuactivitiesclass(groupId=self['encodedKey'], *args, **kwargs)
        activities.attrs = sorted(activities.attrs, key=activityDate)
        self['activities'] = activities
        return 1