 * Accepts strings of length 5 with the first letter being a '6'.
 */
class TestSWrapper6 extends AbstractSerializableValue
{

    public static function isValid($test): bool
    {
        if ($test instanceof self) {
            return true;
        }
        if (is_string($test) && strlen($test) === 5 && $test[0] === "6") {
            return true;
        }