EntityCacheTest.php in drupal/core/modules/system/tests/modules/entity_cache_test_dependency/lib/Drupal/entity_cache_test_dependency/Plugin/Core/Entity/EntityCacheTest.php
TestProcessor.php in drupal/core/modules/aggregator/tests/modules/aggregator_test/lib/Drupal/aggregator_test/Plugin/aggregator/processor/TestProcessor.php