public long runCycle(HollowProducer.Populator task) {
        return runCycle(null, task);
    }
@Test
    public void testPopulateNoChangesVersion() {
        HollowProducer producer = createProducer(tmpFolder);
        long v1 = producer.runCycle(ws -> {
            ws.add(1);
        });
        assertEquals(producer.getCycleCountWithPrimaryStatus(), 1);
        // Run cycle with no changes
        long v2 = producer.runCycle(ws -> {
            ws.add(1);
        });
        assertEquals(producer.getCycleCountWithPrimaryStatus(), 2);
        long v3 = producer.runCycle(ws -> {
            ws.add(2);
        });
        assertEquals(producer.getCycleCountWithPrimaryStatus(), 3);

        assertEquals(v1, v2);
        assertTrue(v3 > v2);
    }