How to find all certain type of pages titles in c5

c5-get-all-page-titles.php

  function getAllPagesList($parent,$type) {

    $page_list = new PageList();
    $page_list->filterByParentID($parent->getCollectionID());
    $page_list->sortByName();
    $page_list->filterByCollectionTypeHandle($type);
    $template_pages = $page_list->get();
    $return_data    = array();

    foreach ($template_pages as $template_page) {
      $title = $template_page->getCollectionName();
      array_push($return_data,$title);
    }
    return $return_data;
  }