1<?php 2 3namespace Drupal\KernelTests\Core\Cache; 4 5use Drupal\Core\Cache\BackendChain; 6use Drupal\Core\Cache\MemoryBackend; 7 8/** 9 * Unit test of the backend chain using the generic cache unit test base. 10 * 11 * @group Cache 12 */ 13class BackendChainTest extends GenericCacheBackendUnitTestBase { 14 15 protected function createCacheBackend($bin) { 16 $chain = new BackendChain(); 17 18 // We need to create some various backends in the chain. 19 $chain 20 ->appendBackend(new MemoryBackend()) 21 ->prependBackend(new MemoryBackend()) 22 ->appendBackend(new MemoryBackend()); 23 24 \Drupal::service('cache_tags.invalidator')->addInvalidator($chain); 25 26 return $chain; 27 } 28 29} 30