How get grouping rows in PHP from EXCEL?

How get grouping rows in PHP from EXCEL?

This code does not issue a groups:

$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader('Xlsx');
$reader->setReadDataOnly(TRUE);
$spreadsheet = $reader->load("bulat_price.xlsx");
$worksheet = $spreadsheet->getActiveSheet();
$worksheet->toArray();

$spreadsheet = PHPExcel_IOFactory::load($file); // load file
$objWorksheet = $spreadsheet->getActiveSheet();
$worksheet = $spreadsheet->setActiveSheetIndex(0); // select firts sheet

$i = 0;
$arrLevel = [];

foreach ($worksheet->getRowDimensions() as $rowDimension) {
    $i++;
    $arrLevel[$i]['level'] = $rowDimension->getOutlineLevel(); // get level
}
$highestColumn = $worksheet->getHighestColumn(); // e.g 'F'

foreach ($objWorksheet->getRowIterator() as $row) {    
    $cellIterator = $row->getCellIterator();
    $cellIterator->setIterateOnlyExistingCells(true);

    foreach ($cellIterator as $cell) {
        $arrLevel[$row->getRowIndex()]["excel"][$cell->getColumn()] = $cell->getValue(); // merge level and value
    }
}

var_dump($arrLevel);

We get:

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