@Override
  public void beforeShipped() throws IOException {
    if (this.currentRow != null) {
      this.currentRow = PrivateCellUtil.createFirstOnRow(CellUtil.copyRow(this.currentRow));
    }
    if (columns != null) {
      columns.beforeShipped();
    }
  }
Delegate to {@link Filter#getNextCellHint(Cell)}. If no filter, return {@code null}.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/querymatcher/ScanQueryMatcher.java