/**
  * Get files of the given type from the backend
  *
  * @param Requirements_Backend $backend
  * @param string $type js or css
  * @return array
  */
 protected function getBackendFiles($backend, $type)
 {
     $type = strtolower($type);
     switch (strtolower($type)) {
         case 'css':
             return $backend->getCSS();
         case 'js':
         case 'javascript':
         case 'script':
             $scripts = $backend->getJavascript();
             return array_combine(array_values($scripts), array_values($scripts));
     }
     return array();
 }