code: public EventDimensions withMetrics(java.util.Map<String, MetricDimension> metrics) {
          setMetrics(metrics);
          return this;
      }
docs: Custom metrics that your app reports to Amazon Pinpoint. You can use these attributes as selection criteria when
  you create an event filter.
  
  @param metrics
  Custom metrics that your app reports to Amazon Pinpoint. You can use these attributes as selection
  criteria when you create an event filter.
  @return Returns a reference to this object so that method calls can be chained together.