anchor.diff:      }
   
       var req = ds.ParamRangeKey.$create(true,
  -        limit: pageSize,
  +        limit: desc ? pageSize * multiplier : pageSize,
           startKey: desc ? list.last.orig.key : list.first.orig.key);
   
       _fetchTs = now;
  
positive.code:     }
  
      var req = ds.ParamRangeKey.$create(empty,
          limit: empty ? pageSize + 1 : pageSize,
          startKey: empty ? null : (desc ? list.first.orig.key : list.last.orig.key));
  
      _fetchTs = now;
  
negative.code:   String errmsg = '';
  
    Store(this.pageSize, this.createFn, this.mergeFn, this.fetchFn, {
      int multiplier = 1,
      bool desc = true,
      List<Pair<T>> list,
    }) : this.multiplier = multiplier, this.desc = desc, this.list = list ?? [] {
      this.mainList = this.list;
    }
  
  