public HollowOrdinalIterator findKeysWithPrefix(String prefix) {
        TST current;
        HollowOrdinalIterator it;
        do {
            current = prefixIndexVolatile;
            it = current.findKeysWithPrefix(prefix);
        } while (current != this.prefixIndexVolatile);
        return it;
    }
@Test
    public void testAutoExpandFieldPath() throws Exception {
        for (Movie movie : getReferenceList()) {
            objectMapper.add(movie);
        }
        StateEngineRoundTripper.roundTripSnapshot(writeStateEngine, readStateEngine);
        HollowPrefixIndex index = new HollowPrefixIndex(readStateEngine, "MovieWithReferenceName", "name.n");// no.value appended, it should work
        Set<Integer> ordinals = toSet(index.findKeysWithPrefix("the"));
        Assert.assertTrue(ordinals.size() == 3);

    }