protected function setRoleProcessorClass($className) {
        if ($this->configured)                                      throw new IllegalStateException('Configuration is frozen');
        if (!is_subclass_of($className, ROLE_PROCESSOR_BASE_CLASS)) throw new StrutsConfigException('Not a subclass of '.ROLE_PROCESSOR_BASE_CLASS.': '.$className);
        $this->roleProcessorClass = $className;
    }