public JmxCollector register() {
        return register(PrometheusRegistry.defaultRegistry);
    }
@Test
    public void nestedTabularDataTest() throws Exception {
        JmxCollector jc = new JmxCollector("---").register(prometheusRegistry);
        assertEquals(
                338,
                getSampleValue(
                        "Hadoop_DataNodeInfo_DatanodeNetworkCounts",
                        new String[] {"service", "key", "key_"},
                        new String[] {"DataNode", "1.2.3.4", "networkErrors"}),
                .001);
    }