DeviceDetector\Parser\OperatingSystem::getAvailableOperatingSystems PHP Method

    public static function getAvailableOperatingSystems()
    {
        return self::$operatingSystems;
    }

 public function getAllOs()
 {
     $allOs = array_keys(OperatingSystem::getAvailableOperatingSystems());
     $allOs = array_map(function ($os) {
         return array($os);
     }, $allOs);
     return $allOs;
 }