@Test
    public void testJsonBindings() {
        IndexVolume indexVolume = JsonUtil.readValue(TEST_JSON, IndexVolume.class);
        Assertions.assertThat(indexVolume)
                .isNotNull();
    }
Use this method to diagnose why your JSON-to-POJO bindings are failing.
stroom-core-shared/src/test/java/stroom/index/shared/TestIndexVolume.java