Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
public function prev()
    {
        if ($this->currentColumnIndex <= $this->startColumnIndex) {
            throw new PhpSpreadsheetException('Column is already at the beginning of range (' . Coordinate::stringFromColumnIndex($this->endColumnIndex) . ' - ' . Coordinate::stringFromColumnIndex($this->endColumnIndex) . ')');
        }
        do {
            --$this->currentColumnIndex;
        } while (($this->onlyExistingCells) && (!$this->worksheet->cellExistsByColumnAndRow($this->currentColumnIndex, $this->rowIndex)) && ($this->currentColumnIndex >= $this->startColumnIndex));
    }
public function prev()
    {
        if ($this->currentColumnIndex <= $this->startColumnIndex) {
            throw new PhpSpreadsheetException('Column is already at the beginning of range (' . Coordinate::stringFromColumnIndex($this->endColumnIndex) . ' - ' . Coordinate::stringFromColumnIndex($this->endColumnIndex) . ')');
        }
        do {
            --$this->currentColumnIndex;
        } while (($this->onlyExistingCells) && (!$this->worksheet->cellExistsByColumnAndRow($this->currentColumnIndex, $this->rowIndex)) && ($this->currentColumnIndex >= $this->startColumnIndex));
    }
Set the iterator to its previous value.

@throws PhpSpreadsheetException