Content to demonstrate the 'clear formatting' button in ckeditor:
public function __construct(
ModuleInstallerInterface $module_installer_service,
Messenger $messenger_service,
ModuleHandlerInterface $module_handler,
ModuleExtensionList $extension_list_module,
StateInterface $state,
) {
parent::__construct();
$this->moduleInstaller = $module_installer_service;
$this->messenger = $messenger_service;
$this->moduleHandler = $module_handler;
$this->extensionListModule = $extension_list_module;
$this->state = $state;
}