'Update metadata item for the snapshot.'

def update_snapshot_metadata_item(self, snapshot_id, id, **kwargs):

    put_body = json.dumps(kwargs)
    url = ('snapshots/%s/metadata/%s' % (snapshot_id, id))
    (resp, body) = self.put(url, put_body)
    body = json.loads(body)
    self.expected_success(200, resp.status)
    return rest_client.ResponseBody(resp, body)
