docs: def last_week_of_year(cls, year):
          """Return the last week of the given year.
          This week with either have week-number 52 or 53.
  
          This will be the same as Week(year+1, 0), but will even work for
          year 9999 where this expression would overflow.
  
          The first week of a given year is simply Week(year, 1), so there
          is no dedicated classmethod for that.
          """
          if year == cls.max.year:
              return cls.max
          return cls(year+1, 0)