Zookeeper unit tester?

[David Rosenstrauch]

Just wondering if there was a mock/fake version of 
org.apache.zookeeper.Zookeeper that could be used for unit testing? 
What I'm envisioning would be a single instance Zookeeper that operates 
completely in memory, with no network or disk I/O.

This would make it possible to pass one of the memory-only 
FakeZookeeper's into unit tests, while using a real Zookeeper in 
production code.

Any such "animal"?  :-)

Thanks,

DR