class Some

class Some extends PagerPluginBase {
  public function summaryTitle() {
    if (!empty($this->options['offset'])) {
      return $this->formatPlural($this->options['items_per_page'], '@count item, skip @skip', '@count items, skip @skip', [
        '@count' => $this->options['items_per_page'],
        '@skip' => $this->options['offset'],
      ]);
    }
    return $this->formatPlural($this->options['items_per_page'], '@count item', '@count items', [
      '@count' => $this->options['items_per_page'],
    ]);
  }
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['items_per_page'] = [
      'default' => 10,
    ];
    $options['offset'] = [
      'default' => 0,
    ];
    return $options;
  }
  
  /**
   * Provide the default form for setting options.
   */
  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
    parent::buildOptionsForm($form, $form_state);
    $pager_text = $this->displayHandler
      ->getPagerText();
    $form['items_per_page'] = [
      '#title' => $pager_text['items per page title'],
      '#type' => 'number',
      '#min' => 0,
      '#description' => $pager_text['items per page description'],
      '#default_value' => $this->options['items_per_page'],
    ];
    $form['offset'] = [
      '#type' => 'number',
      '#min' => 0,
      '#title' => $this->t('Offset (number of items to skip)'),
      '#description' => $this->t('For example, set this to 3 and the first 3 items will not be displayed.'),
      '#default_value' => $this->options['offset'],
    ];
  }
  public function usePager() {
    return FALSE;
  }
  public function useCountQuery() {
    return FALSE;
  }
  public function query() {
    $this->view->query
      ->setLimit($this->options['items_per_page']);
    $this->view->query
      ->setOffset($this->options['offset']);
  }

}