eZ\Publish\Core\Persistence\Cache\LocationHandler::loadSubtreeIds PHP Method

    public function loadSubtreeIds($locationId)
    {
        $cache = $this->cache->getItem('location', 'subtree', $locationId);
        $locationIds = $cache->get();
        if ($cache->isMiss()) {
            $this->logger->logCall(__METHOD__, array('location' => $locationId));
            $cache->set($locationIds = $this->persistenceHandler->locationHandler()->loadSubtreeIds($locationId))->save();
        }
        return $locationIds;
    }