code: private function readMulBlank()
      {
          $length = self::getUInt2d($this->data, $this->pos + 2);
          $recordData = $this->readRecordData($this->data, $this->pos + 4, $length);
  
          // move stream pointer to next record
          $this->pos += 4 + $length;
  
          // offset: 0; size: 2; index to row
          $row = self::getUInt2d($recordData, 0);
  
          // offset: 2; size: 2; index to first column
          $fc = self::getUInt2d($recordData, 2);
  
          // offset: 4; size: 2 x nc; list of indexes to XF records
          // add style information
          if (!$this->readDataOnly && $this->readEmptyCells) {
              for ($i = 0; $i < $length / 2 - 3; ++$i) {
                  $columnString = Coordinate::stringFromColumnIndex($fc + $i + 1);
  
                  // Read cell?
                  if (($this->getReadFilter() !== null) && $this->getReadFilter()->readCell($columnString, $row + 1, $this->phpSheet->getTitle())) {
                      $xfIndex = self::getUInt2d($recordData, 4 + 2 * $i);
                      $this->phpSheet->getCell($columnString . ($row + 1))->setXfIndex($this->mapCellXfIndex[$xfIndex]);
                  }
              }
          }
  
          // offset: 6; size 2; index to last column (not needed)
      }
docs: Read MULBLANK record
  This record represents a cell range of empty cells. All
  cells are located in the same row.
  
  --    "OpenOffice.org's Documentation of the Microsoft
  Excel File Format"