expiration = $expiration; } public function getExpiration() { return $this->expiration; } public function setHistoryId($historyId) { $this->historyId = $historyId; } public function getHistoryId() { return $this->historyId; } } // Adding a class alias for backwards compatibility with the previous class name. class_alias(WatchResponse::class, 'Google_Service_Gmail_WatchResponse');