code: func (h *Histogram) Max() int64 {
  	var max int64
  	i := h.iterator()
  	for i.next() {
  		if i.countAtIdx != 0 {
  			max = i.highestEquivalentValue
  		}
  	}
  	return h.highestEquivalentValue(max)
  }
docs: // Max returns the approximate maximum recorded value.