@Override
  public boolean seekToLastRow() throws IOException {
    if (closed) {
      return false;
    }
    ExtendedCell higherCell = segment.isEmpty() ? null : segment.last();
    if (higherCell == null) {
      return false;
    }

    ExtendedCell firstCellOnLastRow = PrivateCellUtil.createFirstOnRow(higherCell);

    if (seek(firstCellOnLastRow)) {
      return true;
    } else {
      return seekToPreviousRow(higherCell);
    }
  }
Seek the scanner at the first KeyValue of last row
@return true if scanner has values left, false if the underlying data is empty
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/SegmentScanner.java