private static function pop($directory, $partToCheck)
    {
        if ($directory !== null && basename($directory) == $partToCheck) {
            return dirname($directory);
        }
    }
private static function pop($directory, $partToCheck)
    {
        if ($directory !== null && basename($directory) == $partToCheck) {
            return dirname($directory);
        }
    }
@param string|null $directory
@param string      $partToCheck

@return string|null