/**
  * {@inheritdoc}
  */
 public function getDerivativeDefinitions($base_plugin_definition)
 {
     $this->derivatives = array();
     if ($default = $this->searchPageRepository->getDefaultSearchPage()) {
         $active_search_pages = $this->searchPageRepository->getActiveSearchPages();
         foreach ($this->searchPageRepository->sortSearchPages($active_search_pages) as $entity_id => $entity) {
             $this->derivatives[$entity_id] = array('title' => $entity->label(), 'route_name' => 'search.view_' . $entity_id, 'base_route' => 'search.plugins:' . $default, 'weight' => $entity->getWeight());
         }
     }
     return $this->derivatives;
 }