code: def format_date_string(self, date_tuple):
          
          months = ['', 'January', 'February', 'March', 'April', 'May', 'June',
                    'July', 'August', 'September', 'October', 'November', 'December']
          date_string = ''
          if date_tuple.season:
              return '{0}, {1}'.format(date_tuple.season, date_tuple.year)
          else:
              if not date_tuple.month and not date_tuple.day:
                  return '{0}'.format(date_tuple.year)
              if date_tuple.month:
                  date_string += months[int(date_tuple.month)]
              if date_tuple.day:
                  date_string += ' ' + date_tuple.day
              return ', '.join([date_string, date_tuple.year])
docs: Receives a date_tuple object, and outputs a string
          for placement in the article content.