Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Engineering.php
public static function getConversionGroups()
    {
        $conversionGroups = [];
        foreach (self::$conversionUnits as $conversionUnit) {
            $conversionGroups[] = $conversionUnit['Group'];
        }

        return array_merge(array_unique($conversionGroups));
    }
public static function getConversionGroups()
    {
        $conversionGroups = [];
        foreach (self::$conversionUnits as $conversionUnit) {
            $conversionGroups[] = $conversionUnit['Group'];
        }

        return array_merge(array_unique($conversionGroups));
    }
getConversionGroups
Returns a list of the different conversion groups for UOM conversions.

@return array