class NullArgument

class NullArgument extends ArgumentPluginBase {
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['must_not_be'] = [
      'default' => FALSE,
    ];
    return $options;
  }
  
  /**
   * {@inheritdoc}
   */
  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
    parent::buildOptionsForm($form, $form_state);
    $form['must_not_be'] = [
      '#type' => 'checkbox',
      '#title' => $this->t('Fail basic validation if any argument is given'),
      '#default_value' => !empty($this->options['must_not_be']),
      '#description' => $this->t('By checking this field, you can use this to make sure views with more arguments than necessary fail validation.'),
      '#group' => 'options][more',
    ];
    unset($form['exception']);
  }
  
  /**
   * {@inheritdoc}
   */
  protected function defaultActions($which = NULL) {
    if ($which) {
      if (in_array($which, [
        'ignore',
        'not found',
        'empty',
        'default',
      ])) {
        return parent::defaultActions($which);
      }
      return;
    }
    $actions = parent::defaultActions();
    unset($actions['summary asc']);
    unset($actions['summary desc']);
    return $actions;
  }
  
  /**
   * {@inheritdoc}
   */
  public function query($group_by = FALSE) {
  }

}