/**
  * Display information about a collection
  *
  * @param  lang.mirrors.Package $package
  * @param  lang.ClassLoader $loader
  * @param  io.StringWriter $out
  * @return void
  */
 protected function displayCollection($package, $loader, $out)
 {
     $ext = strlen(\xp::CLASS_FILE_EXT);
     $order = ['interface' => [], 'trait' => [], 'enum' => [], 'class' => []];
     // Child packages
     foreach ($loader->packageContents($package->name()) as $entry) {
         $base = $package->isGlobal() ? '' : $package->name() . '.';
         if ('/' === $entry[strlen($entry) - 1]) {
             $out->writeLine('  package ', $base . substr($entry, 0, -1));
         } else {
             if (0 === substr_compare($entry, \xp::CLASS_FILE_EXT, -$ext)) {
                 $mirror = new TypeMirror($loader->loadClass($base . substr($entry, 0, -$ext)));
                 $order[$mirror->kind()->name()][] = self::declarationOf($mirror);
             }
         }
     }
     // Types
     foreach ($order as $type => $types) {
         if (empty($types)) {
             continue;
         }
         $out->writeLine();
         sort($types);
         foreach ($types as $name) {
             $out->writeLine('  ', $name);
         }
     }
 }