Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
public function resetStart($startColumn = 'A')
    {
        $this->startColumnIndex = Coordinate::columnIndexFromString($startColumn);
        $this->adjustForExistingOnlyRange();
        $this->seek(Coordinate::stringFromColumnIndex($this->startColumnIndex));

        return $this;
    }
public function resetStart($startColumn = 'A')
    {
        $this->startColumnIndex = Coordinate::columnIndexFromString($startColumn);
        $this->adjustForExistingOnlyRange();
        $this->seek(Coordinate::stringFromColumnIndex($this->startColumnIndex));

        return $this;
    }
(Re)Set the start column and the current column pointer.

@param string $startColumn The column address at which to start iterating

@throws PhpSpreadsheetException

@return RowCellIterator