/**
* Retrieves the singleton instance of this class.
*
* @param string $cacheFile The file path to save the cache
*
* @return sfSimpleAutoload A sfSimpleAutoload implementation instance.
*/
public static function getInstance($cacheFile = null)
{
if (!isset(self::$instance)) {
self::$instance = new sfSimpleAutoload($cacheFile);
}
return self::$instance;
}
