code: private function writePrintHeaders()
      {
          $record = 0x002a; // Record identifier
          $length = 0x0002; // Bytes to follow
  
          $fPrintRwCol = $this->printHeaders; // Boolean flag
  
          $header = pack('vv', $record, $length);
          $data = pack('v', $fPrintRwCol);
          $this->append($header . $data);
      }
docs: Write the PRINTHEADERS BIFF record.