/**
  * Getting a configuration option.
  * @param key to search for
  * @return mixed result of configuration key.
  * @access public
  * @example CloudFiles::getConfig('username');
  */
 public static function getConfig($key = null)
 {
     if (empty(self::$configs)) {
         Configure::load('cloud_files');
         self::$configs = Configure::read('CloudFiles');
     }
     if (empty($key)) {
         return self::$configs;
     }
     if (isset(self::$configs[$key])) {
         return self::$configs[$key];
     }
     return null;
 }