code: protected Metric serializeValue(String name, Number value, String... path) {
      return new Metric(MetricRegistry.name(name, path), value.doubleValue());
    }
docs: Converts a single key-value pair into a metric.
  
  @param name name of the metric
  @param value value of the metric to report
  @param path additional suffixes to further identify the meaning of the reported value
  @return a {@link org.apache.gobblin.metrics.Metric}.