code: func HumanSizeWithPrecision(size float64, precision int) string {
  	size, unit := getSizeAndUnit(size, 1000.0, decimapAbbrs)
  	return fmt.Sprintf("%.*g%s", precision, size, unit)
  }
docs: // HumanSizeWithPrecision allows the size to be in any precision,
  // instead of 4 digit precision used in units.HumanSize.