public function removeBulkAction($handlerClassName = null, $urlSegment = null)
    {
        if (!$handlerClassName && !$urlSegment) {
            user_error("Provide either a class name or URL segment", E_USER_ERROR);
        }

        foreach ($this->config['actions'] as $url => $class)
        {
            if ($handlerClassName === $class || $urlSegment === $url)
            {
                unset($this->config['actions'][$url]);
                return $this;
            }
        }

        user_error("Bulk action '$handlerClassName' or '$urlSegment' doesn't exists.", E_USER_ERROR);
    }