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