Rollout metrics spec

var spec = RollupMetricSpec.make(
 {
  filter:  "MyFieldName == 'value'",   
  expressions: ["MyMetric"], 
  start: "yyyy-mm-dd",
  end: "yyyy-mm-dd",
  interval: "DAY",
  rollupFunc: "AVG"
 }
);

var metricResult = MyType.rollupMetrics(spec);

c3Viz(metricResult.MyMetric)