docs: def _parse_unit(measure_or_unit_abbreviation):
      """
          Helper function that extracts constant factors from unit specifications.
          This allows to specify units similar to this: 10^6 m^3.
          Return a couple (unit, factor)
      """
      try:
          float(measure_or_unit_abbreviation[0])
          # The measure contains the values and the unit_abbreviation
          factor, unit_abbreviation = measure_or_unit_abbreviation.split(' ', 1)
          return unit_abbreviation, float(factor)
      except ValueError:
          # The measure just contains the unit_abbreviation
          return measure_or_unit_abbreviation, 1.0