Testing using mock.Storage?

Hi,

I have written a Pig Loader and I want to make unit tests for it that
actually use it from Pig.

It's a Maven project and as a first attempt I created a testing class and
tried to create a java based unit test by doing something similar to this:
https://svn.apache.org/repos/asf/pig/trunk/test/org/apache/pig/builtin/mock/TestMockStorage.java

I couldn't get it to work so I copied the exact method testMockStoreAndLoad
and I still get this error:
*java.lang.RuntimeException: No data for location 'bar'*

Does anyone have a suggestion on how to proceed?

Niels Basjes