func NewHandler(hdl Handler) Handler {
	return NewHandlerWith(stats.DefaultEngine, hdl)
}
NewHandler returns a Handler object that warps hdl and produces
metrics on the default engine.
package netstats
import (
	"context"
	"net"
	"github.com/segmentio/stats/v4"
)
type Handler interface {
	ServeConn(ctx context.Context, conn net.Conn)
}