Cach4 demo not function correctly

[greenlaw110]

Go to http://play-rythm-demo.appspot.com/demo/testcache4,

the timestamp in the iframe should change on each refresh when Cache is disabled, while it's always change every 3 seconds without regarding to the cache enabled state.

[hhandoko]

Will check.

[hhandoko]

It returns an NPE when cache is enabled. Need to fix issue #3 first.