code: func LinearBuckets(start, width float64, count int) []float64 {
  	if count < 1 {
  		panic("LinearBuckets needs a positive count")
  	}
  	buckets := make([]float64, count)
  	for i := range buckets {
  		buckets[i] = start
  		start += width
  	}
  	return buckets
  }
docs: // LinearBuckets creates 'count' buckets, each 'width' wide, where the lowest
  // bucket has an upper bound of 'start'. The final +Inf bucket is not counted
  // and not included in the returned slice. The returned slice is meant to be
  // used for the Buckets field of HistogramOpts.
  //
  // The function panics if 'count' is zero or negative.