$array * @return list */ public function shuffleArray(array $array): array {} public function shuffleBytes(string $bytes): string {} /** * @template TKey as array-key * @param array $array * @return list */ public function pickArrayKeys(array $array, int $num): array {} public function __serialize(): array {} public function __unserialize(array $data): void {} } class RandomError extends \Error { } class BrokenRandomEngineError extends RandomError { } class RandomException extends \Exception { } }