public static HollowIncrementalProducer.Builder withProducer(HollowProducer hollowProducer) {
        Builder builder = new Builder();
        return builder.withProducer(hollowProducer);
    }
@Test(expected = IllegalArgumentException.class)
    public void failsWithNoProducer() {
        //No Hollow Producer
        HollowIncrementalProducer.withProducer(null)
                .build();
    }