> content by UIDVALIDITY and UID */ private array $files = []; public function write(string $tenantId, string $serviceId, string $mailbox, int $uidValidity, int $uid, array $content): void { $this->files[$uidValidity][$uid] = $content; } public function delete(string $tenantId, string $serviceId, string $mailbox, int $uidValidity, int ...$uids): void { foreach ($uids as $uid) { unset($this->files[$uidValidity][$uid]); } } public function deleteByMailbox(string $tenantId, string $serviceId, string $mailbox): void { $this->files = []; } /** @return int[] */ public function uids(int $uidValidity): array { $uids = array_keys($this->files[$uidValidity] ?? []); sort($uids); return $uids; } }