18 files declare their use of ThemeExtensionList
- ConfigImporter.php in core/
lib/ Drupal/ Core/ Config/ ConfigImporter.php  - ConfigImportSubscriber.php in core/
lib/ Drupal/ Core/ EventSubscriber/ ConfigImportSubscriber.php  - ConfigSingleImportForm.php in core/
modules/ config/ src/ Form/ ConfigSingleImportForm.php  - ConfigSync.php in core/
modules/ config/ src/ Form/ ConfigSync.php  - ExtensionPathResolverTest.php in core/
tests/ Drupal/ KernelTests/ Core/ Bootstrap/ ExtensionPathResolverTest.php  - InstallConfigurator.php in core/
lib/ Drupal/ Core/ Recipe/ InstallConfigurator.php  - InstallConfiguratorTest.php in core/
tests/ Drupal/ KernelTests/ Core/ Recipe/ InstallConfiguratorTest.php  - InstallerThemeExtensionList.php in core/
lib/ Drupal/ Core/ Installer/ InstallerThemeExtensionList.php  - ModuleRequiredByThemesUninstallValidatorTest.php in core/
tests/ Drupal/ Tests/ Core/ Extension/ ModuleRequiredByThemesUninstallValidatorTest.php  - Recipe.php in core/
lib/ Drupal/ Core/ Recipe/ Recipe.php  - SecurityAdvisoriesFetcher.php in core/
modules/ system/ src/ SecurityAdvisories/ SecurityAdvisoriesFetcher.php  - SystemController.php in core/
modules/ system/ src/ Controller/ SystemController.php  - ThemeController.php in core/
modules/ system/ src/ Controller/ ThemeController.php  - ThemeExperimentalConfirmForm.php in core/
modules/ system/ src/ Form/ ThemeExperimentalConfirmForm.php  - ThemeExtensionListTest.php in core/
tests/ Drupal/ Tests/ Core/ Extension/ ThemeExtensionListTest.php  - ThemeHandlerTest.php in core/
tests/ Drupal/ Tests/ Core/ Extension/ ThemeHandlerTest.php  - ThemeInstallerTest.php in core/
tests/ Drupal/ KernelTests/ Core/ Theme/ ThemeInstallerTest.php  - UpdateManager.php in core/
modules/ update/ src/ UpdateManager.php  
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