Expanded class hierarchy of UpdateKernel in Zircon Profile 8
- class \Drupal\Core\DrupalKernel implements DrupalKernelInterface, TerminableInterface
- class \Drupal\Core\Installer\InstallerKernel
- class \Drupal\Core\Test\TestKernel
- class \Drupal\Core\Test\TestRunnerKernel
- class \Drupal\Core\Update\UpdateKernel