code: public Page<E> moveTo(int pageIndex) {
      if (pageIndex < 1) { throw new RuntimeException("error pageIndex:" + pageIndex); }
      this.pageIndex = pageIndex;
      int toIndex = pageIndex * pageSize;
      SinglePage<E> newPage = new SinglePage<E>(pageIndex, pageSize, datas.size(), datas.subList((pageIndex - 1)
          * pageSize, (toIndex < datas.size()) ? toIndex : datas.size()));
      setPage(newPage);
      return this;
    }
docs: {@inheritDoc}