public function contentTypeGroup($id)
    {
        if ($this->allCleared === true || $this->isSwitchedOff()) {
            return;
        }

        if (is_scalar($id)) {
            // @todo should also clear content type cache for items themselves in case of link/unlink changes, kernel should have a "type-all" tag for this
            $this->cache->invalidateTags(['type-group-' . $id, 'type-map']);
        } else {
            throw new InvalidArgumentType('$id', 'int|null', $id);
        }
    }