fix specify explicit buckets in example (#2493)

* fix specify explicit buckets in example

* add changelog

* Update CHANGELOG.md

Co-authored-by: Anthony Mirabella <a9@aneurysm9.com>

Co-authored-by: Anthony Mirabella <a9@aneurysm9.com>

CHANGELOG.md

@@ -22,6 +22,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 - Fixes the instrument kind for noop async instruments. (#2461)
 - Change the `otlpmetric.Client` interface's `UploadMetrics` method to accept a single `ResourceMetrics` instead of a slice of them. (#2491)
+- Specify explicit buckets in Prometheus example. (#2493)
 
 ## [1.3.0] - 2021-12-10
 

example/prometheus/main.go

@@ -38,7 +38,9 @@ var (
 )
 
 func initMeter() {
-	config := prometheus.Config{}
+	config := prometheus.Config{
+		DefaultHistogramBoundaries: []float64{1, 2, 5, 10, 20, 50},
+	}
 	c := controller.New(
 		processor.NewFactory(
 			selector.NewWithHistogramDistribution(