code: func NewSummaryVec(opts prometheus.SummaryOpts, labelNames []string) *prometheus.SummaryVec {
  	s := prometheus.NewSummaryVec(opts, labelNames)
  	prometheus.MustRegister(s)
  	return s
  }
docs: // NewSummaryVec works like the function of the same name in the prometheus
  // package but it automatically registers the SummaryVec with the
  // prometheus.DefaultRegisterer. If the registration fails, NewSummaryVec
  // panics.