code: protected function sortByRandom()
      {
          $arrFiles  = $this->foundFiles;
          $arrSource = $this->outputBuffer;
  
          if (!$arrFiles) {
              return array('files' => array(), 'source' => array());
          }
  
          $keys  = array_keys($arrFiles);
          $files = array();
          shuffle($keys);
          foreach ($keys as $key) {
              $files[$key] = $arrFiles[$key];
          }
  
          return $this->remapSorting($files, $arrSource);
      }
docs: Shuffle the file list.
  
  @return array