/**
  * Set the class name to use for the default registry instance.
  * Does not affect the currently initialized instance, it only applies
  * for the next time you instantiate.
  *
  * @param string $registryClassName
  * @return void
  * @throws Exception if the registry is initialized or if the
  *   class name is not valid.
  */
 public static function setClassName($registryClassName = 'Syncroton_Registry')
 {
     if (self::$_registry !== null) {
         throw new CakeException('Registry is already initialized');
     }
     if (!is_string($registryClassName)) {
         throw new CakeException("Argument is not a class name");
     }
     /**
      * @see Zend_Loader
      */
     if (!class_exists($registryClassName)) {
         require_once 'Zend/Loader.php';
         Zend_Loader::loadClass($registryClassName);
     }
     self::$_registryClassName = $registryClassName;
 }