Metric constructor

Metric({
  1. required String name,
  2. String? unit,
  3. String? description,
  4. Sum? sum,
  5. Gauge? gauge,
})

Implementation

Metric({
  required this.name,
  this.unit,
  this.description,
  this.sum,
  this.gauge,
  // extend later: histogram, exponentialHistogram, summary …
});