func HandlerWithReset(reg KubeRegistry, opts HandlerOpts) http.Handler {
	defaultHandler := promhttp.HandlerFor(reg, opts.toPromhttpHandlerOpts())
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodDelete {
			reg.Reset()
			io.WriteString(w, "metrics reset\n")
			return
		}
		defaultHandler.ServeHTTP(w, r)
	})
}
HandlerWithReset return an http.Handler with Reset
package metrics
import (
	"io"
	"net/http"
	"github.com/prometheus/client_golang/prometheus/promhttp"
)
const (
	HTTPErrorOnError promhttp.HandlerErrorHandling = iota
	ContinueOnError
	PanicOnError
)
type HandlerOpts promhttp.HandlerOpts
func (ho *HandlerOpts) toPromhttpHandlerOpts() promhttp.HandlerOpts {
	return promhttp.HandlerOpts(*ho)
}
func HandlerFor(reg Gatherer, opts HandlerOpts) http.Handler {
	return promhttp.HandlerFor(reg, opts.toPromhttpHandlerOpts())
}