private function getAllowedBlocks(Zone $zone, LayoutTypeInterface $layoutType)
    {
        if ($layoutType->hasZone($zone->getIdentifier())) {
            $layoutTypeZone = $layoutType->getZone($zone->getIdentifier());
            $allowedBlockDefinitions = $layoutTypeZone->getAllowedBlockDefinitions();

            if (count($allowedBlockDefinitions) > 0) {
                return $allowedBlockDefinitions;
            }
        }

        return true;
    }