def __init__(self, name, host='127.0.0.1', port=27017):
        self.name = name
        self.host = host
        self.port = port
def update_snapshot(self, snapshot_id, **kwargs):
        """Updates a snapshot."""
        put_body = json.dumps({'snapshot': kwargs})
        resp, body = self.put('snapshots/%s' % snapshot_id, put_body)
        body = json.loads(body)
        return resp, body['snapshot']