public static function pluginClassQuestion($suffix = '') {
    $default_class = function ($vars) use ($suffix) {
      $unprefixed_plugin_id = preg_replace('/^' . $vars['machine_name'] . '_/', '', $vars['plugin_id']);
      return Utils::camelize($unprefixed_plugin_id) . $suffix;
    };
    return new Question('Plugin class', $default_class);
  }