modules/jooby-metrics/src/main/java/org/jooby/metrics/Metrics.java
public Metrics reporter(final Function<MetricRegistry, Reporter> callback) {
    return reporter((registry, conf) -> callback.apply(registry));
  }
public Metrics reporter(final Function<MetricRegistry, Reporter> callback) {
    return reporter((registry, conf) -> callback.apply(registry));
  }
Append a {@link Reporter} to the {@link MetricRegistry}.

@param callback Reporter callback.
@return This metrics module.