* @return \pq\Gateway\Table\CacheInterface
*/
function del($key);
+
+ /**
+ * Lock an item
+ * @param string $key
+ * @return \pq\Gateway\Table\CacheInterface
+ */
+ function lock($key);
+
+ /**
+ * Unlock an item
+ * @param string $key
+ * @return \pq\Gateway\Table\CacheInterface
+ */
+ function unlock($key);
}