code: protected List<Metric> serializeGauge(String name, Gauge gauge) {
      List<Metric> metrics = Lists.newArrayList();
      try {
        metrics.add(new Metric(name, Double.parseDouble(gauge.getValue().toString())));
      } catch(NumberFormatException exception) {
        LOGGER.info("Failed to serialize gauge metric. Not compatible with double value.", exception);
      }
      return metrics;
    }
docs: Extracts metrics from {@link com.codahale.metrics.Gauge}.
  
  @param name name of the {@link com.codahale.metrics.Gauge}.
  @param gauge instance of {@link com.codahale.metrics.Gauge} to serialize.
  @return a list of {@link org.apache.gobblin.metrics.Metric}.