sclass HTMLPaginator {
  S startParam = "start";
  int start, step = 50;
  int max; // number of items in list
  
  void processParams(SS params) {
    start = parseInt(params.get(startParam));
  }
  
  S renderNav(O... _) {
    ret pageNav2(hquery(mapMinus(params, 'start)), max, start, step, startParam, _);
  }
  
  IntRange visibleRange() {
    ret intRange(start, min(max, start+step));
  }
}