public JmxCollector register() {
        return register(PrometheusRegistry.defaultRegistry);
    }
@Test
    public void testLowercaseOutputLabelNames() throws Exception {
        new JmxCollector(
                        "\n---\nlowercaseOutputLabelNames: true\nrules:\n- pattern: `^hadoop<service=DataNode, name=DataNodeActivity-ams-hdd001-50010><>replaceBlockOpMinTime:`\n  name: Foo\n  labels:\n    ABC: DEF"
                                .replace('`', '"'))
                .register(prometheusRegistry);
        assertEquals(200, getSampleValue("Foo", new String[] {"abc"}, new String[] {"DEF"}), .001);
    }