<?php/* * This file is part of the Symfony package. * * (c) Fabien Potencier <fabien@symfony.com> * * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */namespaceSymfony\Component\HttpKernel\CacheWarmer;/** * Interface for classes able to warm up the cache. * * @author Fabien Potencier <fabien@symfony.com> */interfaceCacheWarmerInterfaceextendsWarmableInterface{/** * Checks whether this warmer is optional or not. * * Optional warmers can be ignored on certain conditions. * * A warmer should return true if the cache can be * generated incrementally and on-demand. * * @return bool true if the warmer is optional, false otherwise */publicfunctionisOptional();}