private DataRetentionRule createRule(final int num,
                                         final ExpressionOperator expression,
                                         final int age,
                                         final TimeUnit timeUnit) {
        return new DataRetentionRule(num,
                System.currentTimeMillis(),
                "rule " + num,
                true,
                expression,
                age,
                timeUnit,
                false);
    }
Test the archiving stuff.
<p>
Create some old files and make sure they get archived.
stroom-app/src/test/java/stroom/data/store/impl/fs/TestDataRetentionPolicyExecutor.java