PayPal\Api\WebhookEventTypeList::addEventType PHP 메소드

    public function addEventType($webhookEventType)
    {
        if (!$this->getEventTypes()) {
            return $this->setEventTypes(array($webhookEventType));
        } else {
            return $this->setEventTypes(array_merge($this->getEventTypes(), array($webhookEventType)));
        }
    }