@Test
    void testDoWithRefStreamDefinitionLock() {
        final RefStreamDefinition refStreamDefinition = buildUniqueRefStreamDefinition();
        final RefDataOffHeapStore effectiveStore = getEffectiveStore(refStreamDefinition);

        // ensure reentrance works
        effectiveStore.doWithRefStreamDefinitionLock(refStreamDefinition, () -> {
            LOGGER.debug("Got lock");
            effectiveStore.doWithRefStreamDefinitionLock(refStreamDefinition, () -> {
                LOGGER.debug("Got inner lock");
            });
        });
    }
Each task is trying to load data for a different {@link RefStreamDefinition} so they will all be fighting over
the write txn
stroom-pipeline/src/test/java/stroom/pipeline/refdata/store/offheapstore/TestRefDataOffHeapStore.java