/**
  * {@inheritDoc}
  */
 public function extractAuthorsFor($path)
 {
     if (!isset($this->cachedResult[$path])) {
         $result = $this->beautifyAuthorList($this->doExtract($path));
         if (is_array($result)) {
             $authors = array();
             foreach ($result as $author) {
                 $author = $this->config->getRealAuthor($author);
                 if ($author) {
                     $authors[strtolower($author)] = $author;
                 }
             }
             $result = $authors;
         }
         $this->cachedResult[$path] = $result;
     }
     return $this->cachedResult[$path];
 }