docs: def auto(self):
          """Returns the highest whole-number unit."""
          if self._value >= 1099511627776:
              return self.TiB, 'TiB'
          if self._value >= 1073741824:
              return self.GiB, 'GiB'
          if self._value >= 1048576:
              return self.MiB, 'MiB'
          if self._value >= 1024:
              return self.KiB, 'KiB'
          else:
              return self.B, 'B'