_id example

    public function load($id, $doNotTestCacheValidity = false, $doNotUnserialize = false)
    {
        if (!$this->_options['caching']) {
            return false;
        }
        $id = $this->_id($id); // cache id may need prefix         $this->_lastId = $id;
        self::_validateIdOrTag($id);

        $this->_log("Zend_Cache_Core: load item '{$id}'", 7);
        $data = $this->_backend->load($id, $doNotTestCacheValidity);
        if ($data === false) {
            // no cache available             return false;
        }
        if ((!$doNotUnserialize) && $this->_options['automatic_serialization']) {
            // we need to unserialize before sending the result