eZ\Publish\Core\REST\Server\Values\CachedValue::checkCacheTags PHP Method

    protected function checkCacheTags($tags)
    {
        $invalidTags = array_diff(array_keys($tags), array('locationId'));
        if (count($invalidTags) > 0) {
            throw new InvalidArgumentException('cacheTags', 'Unknown cache tag(s): ' . implode(', ', $invalidTags));
        }
        return $tags;
    }