private function setInstanceOptions(array $options = array())
    {
        foreach ($options as $key => $value) {
            if (true === array_key_exists($key, $this->_instance_options)) {
                $this->_instance_options[$key] = $value;
            } else {
                throw new CacheException(sprintf('Unknown option %s for cache adapter %s.', $key, get_class($this)));
            }
        }

        return $this;
    }