DrupalKernelTest.php in core/tests/Drupal/KernelTests/Core/DrupalKernel/DrupalKernelTest.php
KernelPreHandle.php in core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php
LanguageRequestSubscriber.php in core/modules/language/src/EventSubscriber/LanguageRequestSubscriber.php
ModifyServiceDefinitionsPass.php in core/lib/Drupal/Core/DependencyInjection/Compiler/ModifyServiceDefinitionsPass.php
ServerCommand.php in core/lib/Drupal/Core/Command/ServerCommand.php
UpdateRoot.php in core/modules/update/src/UpdateRoot.php