Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Worksheet.php
public function duplicateConditionalStyle(array $pCellStyle, $pRange = '')
    {
        foreach ($pCellStyle as $cellStyle) {
            if (!($cellStyle instanceof Conditional)) {
                throw new Exception('Style is not a conditional style');
            }
        }

        // Calculate range outer borders
        list($rangeStart, $rangeEnd) = Coordinate::rangeBoundaries($pRange . ':' . $pRange);

        // Make sure we can loop upwards on rows and columns
        if ($rangeStart[0] > $rangeEnd[0] && $rangeStart[1] > $rangeEnd[1]) {
            $tmp = $rangeStart;
            $rangeStart = $rangeEnd;
            $rangeEnd = $tmp;
        }

        // Loop through cells and apply styles
        for ($col = $rangeStart[0]; $col <= $rangeEnd[0]; ++$col) {
            for ($row = $rangeStart[1]; $row <= $rangeEnd[1]; ++$row) {
                $this->setConditionalStyles(Coordinate::stringFromColumnIndex($col) . $row, $pCellStyle);
            }
        }

        return $this;
    }
public function duplicateConditionalStyle(array $pCellStyle, $pRange = '')
    {
        foreach ($pCellStyle as $cellStyle) {
            if (!($cellStyle instanceof Conditional)) {
                throw new Exception('Style is not a conditional style');
            }
        }

        // Calculate range outer borders
        list($rangeStart, $rangeEnd) = Coordinate::rangeBoundaries($pRange . ':' . $pRange);

        // Make sure we can loop upwards on rows and columns
        if ($rangeStart[0] > $rangeEnd[0] && $rangeStart[1] > $rangeEnd[1]) {
            $tmp = $rangeStart;
            $rangeStart = $rangeEnd;
            $rangeEnd = $tmp;
        }

        // Loop through cells and apply styles
        for ($col = $rangeStart[0]; $col <= $rangeEnd[0]; ++$col) {
            for ($row = $rangeStart[1]; $row <= $rangeEnd[1]; ++$row) {
                $this->setConditionalStyles(Coordinate::stringFromColumnIndex($col) . $row, $pCellStyle);
            }
        }

        return $this;
    }
Duplicate conditional style to a range of cells.

Please note that this will overwrite existing cell styles for cells in range!

@param Conditional[] $pCellStyle Cell style to duplicate
@param string $pRange Range of cells (i.e. "A1:B10"), or just one cell (i.e. "A1")

@throws Exception

@return Worksheet