class Stub

class Stub {
    public const TYPE_REF = 1;
    public const TYPE_STRING = 2;
    public const TYPE_ARRAY = 3;
    public const TYPE_OBJECT = 4;
    public const TYPE_RESOURCE = 5;
    public const TYPE_SCALAR = 6;
    public const STRING_BINARY = 1;
    public const STRING_UTF8 = 2;
    public const ARRAY_ASSOC = 1;
    public const ARRAY_INDEXED = 2;
    public int $type = self::TYPE_REF;
    public string|int|null $class = '';
    public mixed $value = null;
    public int $cut = 0;
    public int $handle = 0;
    public int $refCount = 0;
    public int $position = 0;
    public array $attr = [];
    private static array $defaultProperties = [];
    
    /**
     * @internal
     */
    public function __sleep() : array {
        $properties = [];
        if (!isset(self::$defaultProperties[$c = static::class])) {
            $reflection = new \ReflectionClass($c);
            self::$defaultProperties[$c] = [];
            foreach ($reflection->getProperties() as $p) {
                if ($p->isStatic()) {
                    continue;
                }
                self::$defaultProperties[$c][$p->name] = $p->hasDefaultValue() ? $p->getDefaultValue() : ($p->hasType() ? NoDefault::NoDefault : null);
            }
        }
        foreach (self::$defaultProperties[$c] as $k => $v) {
            if (NoDefault::NoDefault === $v || $this->{$k} !== $v) {
                $properties[] = $k;
            }
        }
        return $properties;
    }

}