func PopulateNormalHistogram(h metrics.Histogram, seed int) {
	r := rand.New(rand.NewSource(int64(seed)))
	for i := 0; i < Count; i++ {
		sample := r.NormFloat64()*float64(Stdev) + float64(Mean)
		if sample < 0 {
			sample = 0
		}
		h.Observe(sample)
	}
}
PopulateNormalHistogram makes a series of normal random observations into the
histogram. The number of observations is determined by Count. The randomness
is determined by Mean, Stdev, and the seed parameter.

This is a low-level function, exported only for metrics that don't perform
dynamic quantile computation, like a Prometheus Histogram (c.f. Summary). In
most cases, you don't need to use this function, and can use TestHistogram
instead.
package teststat
import (
	"math"
	"math/rand"
	"github.com/go-kit/kit/metrics"
)