public function buildConfigurationForm($form, FormStateInterface $form_state)
 {
     $config_form = parent::buildConfigurationForm($form, $form_state);
     $replacements = $this->getDefinitionValue('replacements');
     if (isset($replacements['base_path'])) {
         $config_form['base_path'] = ['#type' => 'textfield', '#title' => $this->t('Base View Path'), '#description' => $this->t('@todo add description'), '#default_value' => $replacements['base_path'], '#required' => TRUE];
     }
     return $config_form;
 }
 /**
  * {@inheritdoc}
  */
 public function alterViewTemplateAfterCreation(array &$view_template, $options = NULL)
 {
     parent::alterViewTemplateAfterCreation($view_template, $options);
     // Make a simple change. This one goes to 11!
     $view_template['display']['default']['display_options']['pager']['options']['items_per_page'] = $options['pager_count'];
 }