docs: def humanize(number):
      """ Return a human-readable string for number. """
      # units = ('bytes', 'KB', 'MB', 'GB', 'TB')
      # base = 1000
      units = ('bytes', 'KiB', 'MiB', 'GiB', 'TiB')
      base = 1024
      if number is None:
          return None
      pow = int(math.log(number, base)) if number > 0 else 0
      pow = min(pow, len(units) - 1)
      mantissa = number / (base ** pow)
      return "%.4g %s" % (mantissa, units[pow])