public String prometheusName(String recordName,
                               String metricName) {
    String baseName = StringUtils.capitalize(recordName)
        + StringUtils.capitalize(metricName);
    String[] parts = SPLIT_PATTERN.split(baseName);
    String joined =  String.join("_", parts).toLowerCase();
    return DELIMITERS.matcher(joined).replaceAll("_");
  }
@Test
  public void testNamingCamelCase() {
    PrometheusMetricsSink sink = new PrometheusMetricsSink();

    Assert.assertEquals("rpc_time_some_metrics",
        sink.prometheusName("RpcTime", "SomeMetrics"));

    Assert.assertEquals("om_rpc_time_om_info_keys",
        sink.prometheusName("OMRpcTime", "OMInfoKeys"));

    Assert.assertEquals("rpc_time_small",
        sink.prometheusName("RpcTime", "small"));
  }