Using collection as options for select

public static function getPageTitle($collection_options, $path)
{

    $grav = Grav::instance();
    $page = $grav['page'];
    $collection = $page->evaluate([$collection_options => $path]);
    $titles = [];

    foreach ($collection as $item) {
        $titles[$item->title()] = $item->title();
    }

    return $titles;
}

header.taxonomy.myselect:
   type: select
   label: My Label
   multiple: true
   data-options@: ['\Grav\Theme\Themename::getPageTitle', '@page.modular', '/path']
   validate:
      type: commalist