public static function registerRedactorPlugin(string $plugin)
    {
        if (isset(self::$_registeredPlugins[$plugin])) {
            return;
        }

        $paths = self::redactorPluginPaths();

        foreach ($paths as $registeredPath) {
            foreach (["{$registeredPath}/{$plugin}", $registeredPath] as $path) {
                if (file_exists("{$path}/{$plugin}.js")) {
                    $view = Craft::$app->getView();
                    $baseUrl = Craft::$app->getAssetManager()->getPublishedUrl($path, true);
                    $view->registerJsFile("{$baseUrl}/{$plugin}.js", [
                        'depends' => RedactorAsset::class
                    ]);
                    // CSS file too?
                    if (file_exists("{$path}/{$plugin}.css")) {
                        $view->registerCssFile("{$baseUrl}/{$plugin}.css");
                    }
                    // Don't do this twice
                    self::$_registeredPlugins[$plugin] = true;
                    return;
                }
            }
        }

        throw new InvalidConfigException('Redactor plugin not found: '.$plugin);
    }