diff --git a/prometheus/histogram_test.go b/prometheus/histogram_test.go index f2fb5bb8c..c2a14ae72 100644 --- a/prometheus/histogram_test.go +++ b/prometheus/histogram_test.go @@ -1049,10 +1049,14 @@ func TestNativeHistogramConcurrency(t *testing.T) { go func(vals []float64) { start.Wait() - for _, v := range vals { + for i, v := range vals { // An observation every 1 to 10 seconds. atomic.AddInt64(&ts, rand.Int63n(10)+1) - his.Observe(v) + if i%2 == 0 { + his.Observe(v) + } else { + his.(ExemplarObserver).ObserveWithExemplar(v, Labels{"foo": "bar"}) + } } end.Done() }(vals)