@Override
        public Integer copy(Integer current) {
            return current;
        }
Smoke test for multi producer data structure.

<p>
TODO sorely needs nastier cases
</p>

@author <a href="mailto:steinar@yahoo-inc.com">Steinar Knutsen</a>
vespajlib/src/test/java/com/yahoo/concurrent/ThreadLocalDirectoryTestCase.java