'Get the result for a group by id.'

def _restore_group(self, group_id):

    obj = self.group_collection.find_one({u'_id': group_id})
    if obj:
        return {u'task_id': obj[u'_id'], u'date_done': obj[u'date_done'], u'result': [self.app.AsyncResult(task) for task in self.decode(obj[u'result'])]}
