Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
public function prev()
    {
        if ($this->currentRow <= $this->startRow) {
            throw new PhpSpreadsheetException("Row is already at the beginning of range ({$this->startRow} - {$this->endRow})");
        }

        do {
            --$this->currentRow;
        } while (($this->onlyExistingCells) &&
            (!$this->worksheet->cellExistsByColumnAndRow($this->columnIndex, $this->currentRow)) &&
            ($this->currentRow >= $this->startRow));
    }
public function prev()
    {
        if ($this->currentRow <= $this->startRow) {
            throw new PhpSpreadsheetException("Row is already at the beginning of range ({$this->startRow} - {$this->endRow})");
        }

        do {
            --$this->currentRow;
        } while (($this->onlyExistingCells) &&
            (!$this->worksheet->cellExistsByColumnAndRow($this->columnIndex, $this->currentRow)) &&
            ($this->currentRow >= $this->startRow));
    }
Set the iterator to its previous value.