code: func NewHistogram(opts HistogramOpts) Histogram {
  	return newHistogram(
  		NewDesc(
  			BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
  			opts.Help,
  			nil,
  			opts.ConstLabels,
  		),
  		opts,
  	)
  }
docs: // NewHistogram creates a new Histogram based on the provided HistogramOpts. It
  // panics if the buckets in HistogramOpts are not in strictly increasing order.