code: public function collectDir($dir, $ext = '.twig')
      {
          $iterator = new RegexIterator(
              new RecursiveIteratorIterator(
                  new RecursiveDirectoryIterator($dir), RecursiveIteratorIterator::LEAVES_ONLY
              ), '{'.preg_quote($ext).'$}'
          );
  
          return $this->collect(new Twig_Util_TemplateDirIterator($iterator));
      }
docs: Returns deprecations for templates contained in a directory.
  
  @param string $dir A directory where templates are stored
  @param string $ext Limit the loaded templates by extension
  
  @return array An array of deprecations