stopMetric method
Stops a metric previously started and adds it to metrics. See startMetric.
Implementation
Duration? stopMetric(String name, {DateTime? now}) {
var metric = _startedMetrics?[name];
if (metric == null) return null;
now ??= DateTime.now();
var duration = now.difference(metric.start);
setMetric(name, duration: duration, description: metric.description);
return duration;
}