public void pageDown() {
    if (pageSize > 0 && currentPosition < recordsSize - 1) {

      currentPosition = currentPosition + pageSize;
      if (currentPosition >= recordsSize) {
        currentPosition = recordsSize - 1;
      }

      pageStartPosition = currentPosition;
      pageEndPosition = pageStartPosition + pageSize;
      keepConsistent();
    }
  }
Utility class for paging for the metrics.
hbase-hbtop/src/main/java/org/apache/hadoop/hbase/hbtop/screen/top/Paging.java