public boolean addTagToPhoto(String photoId, List<String> toUserIds) throws FacebookException {
        ensureAuthorizationEnabled();
        if (toUserIds.size() == 0) throw new IllegalArgumentException("toUserIds size 0");
        if (toUserIds.size() == 1) {
            return addTagToPhoto(photoId, toUserIds.get(0));
        }
        List<Map<String, String>> tags = new ArrayList<Map<String, String>>(toUserIds.size());
        for (String toUserId : toUserIds) {
            Map<String, String> map = new HashMap<String, String>(1);
            map.put("tag_uid", toUserId);
            tags.add(map);
        }
        HttpResponse res = post(buildEndpoint(photoId, "tags"), new HttpParameter[]{new HttpParameter("tags", new JSONArray(tags).toString())});
        return parseBoolean(res);
    }