code: def by_month(self, chamber, year=None, month=None):
          
          check_chamber(chamber)
  
          now = datetime.datetime.now()
          year = year or now.year
          month = month or now.month
  
          path = "{chamber}/votes/{year}/{month}.json".format(
              chamber=chamber, year=year, month=month)
          return self.fetch(path, parse=lambda r: r['results'])
docs: Return votes for a single month, defaulting to the current month.