This patch by Pan Jie adds a cache-invalidation test case, how it works:
tree40ad23da3bd88217f494269e593249b782cb8e5c
-rw-r--r-- 3648 BUILD-JAVA
-rw-r--r-- 2047 COMMITTERS
-rw-r--r-- 498 DISCLAIMER
-rw-r--r-- 16707 LICENSE
-rw-r--r-- 1796 NOTICE
-rw-r--r-- 515 README
drwxr-xr-x - assembly
drwxr-xr-x - config
drwxr-xr-x - etc
drwxr-xr-x - features
drwxr-xr-x - java
drwxr-xr-x - javascript
drwxr-xr-x - php
-rw-r--r-- 48201 pom.xml
drwxr-xr-x - site