48 files declare their use of Language in Drupal 9
- AliasManagerTest.php in core/modules/ path_alias/ tests/ src/ Unit/ AliasManagerTest.php 
- ConfigEntityBaseUnitTest.php in core/tests/ Drupal/ Tests/ Core/ Config/ Entity/ ConfigEntityBaseUnitTest.php 
- Contains \Drupal\Tests\Core\Config\Entity\ConfigEntityBaseUnitTest.
- ConfigEntityStorageTest.php in core/tests/ Drupal/ Tests/ Core/ Config/ Entity/ ConfigEntityStorageTest.php 
- ConfigMapperManagerTest.php in core/modules/ config_translation/ tests/ src/ Unit/ ConfigMapperManagerTest.php 
- ConfigNamesMapperTest.php in core/modules/ config_translation/ tests/ src/ Unit/ ConfigNamesMapperTest.php 
- Contains \Drupal\Tests\config_translation\Unit\ConfigNamesMapperTest.
- ConfigOverridesPriorityTest.php in core/tests/ Drupal/ KernelTests/ Core/ Config/ ConfigOverridesPriorityTest.php 
- ConfigSubscriber.php in core/modules/ language/ src/ EventSubscriber/ ConfigSubscriber.php 
- ConfigTranslationController.php in core/modules/ config_translation/ src/ Controller/ ConfigTranslationController.php 
- ConfigTranslationUiTest.php in core/modules/ config_translation/ tests/ src/ Functional/ ConfigTranslationUiTest.php 
- ConfigurableLanguageManager.php in core/modules/ language/ src/ ConfigurableLanguageManager.php 
- ContentEntityBase.php in core/lib/ Drupal/ Core/ Entity/ ContentEntityBase.php 
- ContentEntityBaseUnitTest.php in core/tests/ Drupal/ Tests/ Core/ Entity/ ContentEntityBaseUnitTest.php 
- ContentTranslationManageAccessCheckTest.php in core/modules/ content_translation/ tests/ src/ Unit/ Access/ ContentTranslationManageAccessCheckTest.php 
- ContentTranslationSettingsTest.php in core/modules/ content_translation/ tests/ src/ Functional/ ContentTranslationSettingsTest.php 
- ContentTranslationUITestBase.php in core/modules/ content_translation/ tests/ src/ Functional/ ContentTranslationUITestBase.php 
- DateFormatter.php in core/lib/ Drupal/ Core/ Datetime/ DateFormatter.php 
- DefaultLanguageItem.php in core/modules/ language/ src/ DefaultLanguageItem.php 
- DrupalKernel.php in core/lib/ Drupal/ Core/ DrupalKernel.php 
- EntityAdapterUnitTest.php in core/tests/ Drupal/ Tests/ Core/ Entity/ TypedData/ EntityAdapterUnitTest.php 
- EntityBase.php in core/lib/ Drupal/ Core/ Entity/ EntityBase.php 
- EntityFieldManagerTest.php in core/tests/ Drupal/ Tests/ Core/ Entity/ EntityFieldManagerTest.php 
- Contains \Drupal\Tests\Core\Entity\EntityFieldManagerTest.
- EntityLinkTest.php in core/tests/ Drupal/ Tests/ Core/ Entity/ EntityLinkTest.php 
- EntityRepositoryTest.php in core/tests/ Drupal/ Tests/ Core/ Entity/ EntityRepositoryTest.php 
- EntityTypeBundleInfoTest.php in core/tests/ Drupal/ Tests/ Core/ Entity/ EntityTypeBundleInfoTest.php 
- EntityUnitTest.php in core/tests/ Drupal/ Tests/ Core/ Entity/ EntityUnitTest.php 
- FieldEntityTranslationTest.php in core/modules/ views/ tests/ src/ Functional/ Entity/ FieldEntityTranslationTest.php 
- FieldPluginBaseTest.php in core/modules/ views/ tests/ src/ Unit/ Plugin/ field/ FieldPluginBaseTest.php 
- Contains \Drupal\Tests\views\Unit\Plugin\field\FieldPluginBaseTest.
- FieldRenderedEntityTranslationTest.php in core/modules/ views/ tests/ src/ Functional/ Entity/ FieldRenderedEntityTranslationTest.php 
- FilterKernelTest.php in core/modules/ filter/ tests/ src/ Kernel/ FilterKernelTest.php 
- install.core.inc in core/includes/ install.core.inc 
- API functions for installing Drupal.
- InstallerTestBase.php in core/tests/ Drupal/ FunctionalTests/ Installer/ InstallerTestBase.php 
- KernelTestBase.php in core/tests/ Drupal/ KernelTests/ KernelTestBase.php 
- LanguageCustomLanguageConfigurationTest.php in core/modules/ language/ tests/ src/ Functional/ LanguageCustomLanguageConfigurationTest.php 
- LanguageListTest.php in core/modules/ language/ tests/ src/ Functional/ LanguageListTest.php 
- LanguageUILanguageNegotiationTest.php in core/modules/ language/ tests/ src/ Functional/ LanguageUILanguageNegotiationTest.php 
- LanguageUnitTest.php in core/tests/ Drupal/ Tests/ Core/ Language/ LanguageUnitTest.php 
- LanguageUrlRewritingTest.php in core/modules/ language/ tests/ src/ Functional/ LanguageUrlRewritingTest.php 
- LinkGeneratorTest.php in core/tests/ Drupal/ Tests/ Core/ Utility/ LinkGeneratorTest.php 
- LocaleConfigSubscriberForeignTest.php in core/modules/ locale/ tests/ src/ Kernel/ LocaleConfigSubscriberForeignTest.php 
- MailHandlerTest.php in core/modules/ contact/ tests/ src/ Unit/ MailHandlerTest.php 
- PathProcessorTest.php in core/tests/ Drupal/ Tests/ Core/ PathProcessor/ PathProcessorTest.php 
- SeparatorTranslationTest.php in core/modules/ datetime_range/ tests/ src/ Kernel/ SeparatorTranslationTest.php 
- ShortcutTranslationUITest.php in core/modules/ shortcut/ tests/ src/ Functional/ ShortcutTranslationUITest.php 
- SqlContentEntityStorageTest.php in core/tests/ Drupal/ Tests/ Core/ Entity/ Sql/ SqlContentEntityStorageTest.php 
- Contains \Drupal\Tests\Core\Entity\Sql\SqlContentEntityStorageTest.
- TranslationLinkTest.php in core/modules/ content_translation/ tests/ src/ Functional/ Views/ TranslationLinkTest.php 
- UpdatePathTestBase.php in core/tests/ Drupal/ FunctionalTests/ Update/ UpdatePathTestBase.php 
- UrlTest.php in core/modules/ system/ tests/ src/ Kernel/ Common/ UrlTest.php 
- UserValidationTest.php in core/modules/ user/ tests/ src/ Kernel/ UserValidationTest.php 
