private function checkPlaylistsForReindex()
 {
     // check for media items which which should be reindexed because their accessibiliy has changed
     $playlistsToReindex = Playlist::upToDateInIndex()->where(function ($q) {
         $q->where(function ($q) {
             $q->accessibleToPublic()->where("in_index", false);
         })->orWhere(function ($q) {
             $q->notAccessibleToPublic()->where("in_index", true);
         });
     })->get();
     foreach ($playlistsToReindex as $a) {
         // touching will increment the version number
         $a->touch();
         $this->info("Playlist with id " . $a->id . " queued for reindex.");
     }
 }